This video is appropriate for the height from which the objects are dropped. Of course from 100m air resistance becomes significant. So a result that applies to one situation does not necessarily apply to others. In science we must be careful about generalising our findings to different situations where our assumptions may no longer be valid.
@Pal mernoudaz. It has been done on moon by astronauts just not with basketballs. One object was a feather and other can’t remember for sure but much heavier object like a hammer. And they hit at same time. They also have huge chambers on earth which they can suck all the air out of and dropped objects from much greater height with same result.
no, it really is true. Do the experiment. You can see in this video that they certainly do not land half a second apart. Things like not being dropped perfectly simultaneously and from the exact same height play a bigger role in this case than air resistance.
@@rajarshimukherjee4844 F=Ma anf F=GM1M2/r^2 Equate the values of F and The Mass of the ball will cancel out leaving the mass of the Earth M2. Therefore the Force acting on both balls is different but they cancel there own mass as heavier ball needs more force to attain that same acceleration.
+don gerkin The best of the best. This is why i think people should stop studying their dumbass social sciences and get a degree in things that aren't still points of contention.
Gravitation is an interesting concept. Taking account Newton's third law, when you drop something the only thing moving is not the object you dropped but also the Earth is accelerating towards your falling object. The amount of the Earth's movement is immeasurably tiny because of the humongous inertia of the Earth but it's indeed possible to calculate. Also the Moon does not circle the Earth, rather they both circle around their combined center of mass which happens to be inside of the Earth.
In a vacuum, they will both fall at the same rate and hit the ground at the same time. But if dropped from a higher distance outside, the black one will hit the ground first because the lighter basketball will succumb to air resistance.
+Odspotikins True, the magnitude of the force of air resistance would be the same for each, but the basketball would decelerate more quickly than the medicine ball since it has less mass. The medicine ball would still hit the ground first.
However, if dropped separately, even in a vacuum, although the gravitational force from earth to each ball divided by their inertia is exactly the same, each ball exerts a (very, very tiny) gravitational force on the earth, accelerating the earth to the ball. The gravitational pull of the more massive ball will give the earth more weight with respect to the ball than the less massive ball would. So, the time for the more massive ball and earth to collide from a set distance (from an outside perspective, because the inertia of the earth is much greater than that of either ball we would just interpret the event as the ball falling to earth) would be less than that of the less massive ball.
+Niko Yochum Same shape, same resisting force, but the bowling ball have more inercia, so it will "feel" less aceleration.A=F/M aceleration is the force divide by the mass, if the force is the same, the one with more mass got less decelaration.
I'm glad I watch these videos of yours where I already know the answer, because I didn't realise until the end that I didn't know WHY. Thanks for explaining the mass/inertia bit.
ParaditeRs Mm and not every1 finish school either.. or don't pay attention at all/buy their way to the next grade, or crap school or a giving teacher & then not watch interesting science videos like these on youtube as well
@kire271MK First, let me say that all discussion of terminal velocity and air resistance is irrelevant to this experiment because the balls clearly aren't falling far enough for air effects to be noticeable. Second, the gravitational force on the balls is NOT the same. When you pick up the medicine ball, you notice is has a much greater attraction to the Earth. Yes, the resulting accelerations are the same, and that is because the inertia of the medicine ball is proportionately greater.
"Not enough for air to be noticeable" is not the same thing as "not enough for air to matter" It does still matter, and the medicine ball WILL still hit first all other things being equal, whether your poorly set up experiment is able to allow it to be noticed from the noisy muscle inconsistencies or not. Which normally wouldn't be a big deal, except for when you go around telling students that they're wrong for guessing that when they are not wrong for guessing that......
Veritasium don't know if you'll see this reply, but just wanted to say you looked so young, like literally so different 10 years ago that I had to make sure it was you, Derek and not somebody else. It was only after looking at the fact that the video was posted 10 years ago and your voice and little face similarity that I could tell that it was you.
Acceleration is independent of mass, therefore if you ignore air resistance AKA drag force, they accelerate at the same rate and thus hit the ground simultaneously. Factoring in air resistance, two extra facts are relevant: drag force is dependent on the velocity of the object, and a lighter object has a smaller terminal velocity. Until both objects accelerate past the lighter object's terminal velocity, they will be "dragged" the same amount (which changes equally for both as they accelerate), meaning they still accelerate at the same rate and hit the ground at the exact same time. But if the lighter object hits its terminal velocity, gravity and drag balance out and it stops accelerating. So if and only if both balls fall long enough to allow their speeds to accelerate pass the basketball's terminal velocity, the medicine ball will hit the ground first.
1betrieb1 the buoyancy of the objects (in what I am assuming is air) is like saying the force of air against the objects, which equates to the friction, meaning it is neglected... I think. I am unfamiliar with buoyancy, for I am only a highschool graduate :)
10 years later and you're production quality has improved and your subscribers have skyrocketed, but your humbleness has stayed the same. Here's to more years of success to this channel.
My thoughts on this, since I learned of this in elementary school science, is that the aerodynamics of the object have more of an effect on its acceleration than any mass/weight. Of course, this goes right out the window in a perfect vacuum. (Thank you, Bill Nye.) I've always had issues with this demonstration for this reason. Cool videos, but man o man, am I glad you got better at this the further this channel's gone on.
2. Buoyancy which depends not on the mass but the density of the balls. 3. Its not just the ball falling towards the earth but the earth is also falling towards the ball. This factor would make the heavier ball hit the earth first since the earth would be “falling” towards the ball a little faster.
When I was recreating this with random objects decided to drop a can of bug spray and it broke the cap so when I picked it up it sprayed directly in my eyes...
ok, nobody learns physics at first grade. you most likely learned it at the age of 12 (unless you taught yourself at home). or maybe wherever you're from you learn it early. how should I know?
Once I had to convince, my friend how objects fall in air (he just insisted on misunderstood school half knowledge that all things fall the same). I let two cans of Coke falling down from the tenth floor at the same time. One can was full and the other was empty (opening closed). The full can was the first to reach the floor by a clear intervall. And it bursts completely. The empty can had no scratches. For better understanding it helped my friend to imagine two sinking balls in honey-like fluid, one very heavy weighted and one distinctly lighter. But it was a real hard concept changing process for him. The heavier ball reaches a higher sinking velocity in the end (as one of the girls in the video said). Both balls with clearly different gravity forces accelerate until air friction compensates these different forces (so the heavier ball gets more time of acceleration until compensation. And the phenomenon that the quantum of force of air resistance depends on the speed, has been experienced by everyone who has ever held a hand out of an accelerating car)... But to be correct, the real question was: which of the two balls in the video lands first from a height of about 2 m? I don't think, that the lighter ball reaches its end velocity within this short distance and so it most likely keeps up with the heavier one (empirical evidence pending).
Inertia and gravitational force balance each other. So they fall on the ground at the same time. Air resistance can be negligible, they are almost in the same conditions (material, shape)
The best part of this video was the girl that thought the basketball might actually go up because it had air in it. I had to rewind it to make sure I actually heard that correctly.
It works only because the balls are dropped from a couple of meter. Drop them from 200 meters and the black one will reach the ground first. The force due to gravity is different but the resulting acceleration the same. The force due to air resistance is the same but it generates a higher acceleration on the basket ball. But to have air resistance to actually work you need a longer drop. I'm not sure inertia has anything to do with gravitational acceleration.
+rikirikibis Both the gravitational acceleration and inertia are relative to mass, so increasing the mass increases both, causing no difference in the rate of change of velocity. In an ideal universe, at least.
Maybe so, but that was before the internet was invented and people decided they didn't need to know anything any more! (It was Galileo Galilei that did the experiment).
Not true, every object that is linked with earth's gravity will drop at the same rate. This however is changed by the air resistant. This has been tested many times before. Mass does not play a roll on what gravity pulls in faster, because it can't.
You are all saying the answer is obvious but it's not. I totally understand the reason but this is mostly counterintuitive. Almost every human thinks something lighter would take more time to reach the ground because most things that are lighter like a balloon, plastic bag, feathers take longer than let's say a tennis ball or a jacket. Because of this, we would quickly draw conclusion and associate an object's weight with how fast it would fall so it makes sense that almost everyone is wrong in this video. My point is, the most intuitive way to think is a feather is lighter than a ball, a feather takes longer to hit the ground than a ball, therefore, a lighter object takes longer to hit the ground than a heavier object(which is wrong but that's the most intuitive way). an average person wouldn't pay that much attention to something like air resistance and inertia.
Also, being the height of the fall is 'very very high', both balls would probably reach their terminal velocities, and that speed is higher for the more massive object. Terminal velocity is when the force of drag is equal to the force of gravity. Since the force of gravity is greater on the more massive ball, then the force of drag required to counter gravity is also greater. Since the objects have different masses, but are otherwise identical, the only variable that can affect drag is speed.
If you were to do the experiment in such a way that the drop was automated, perfectly similar and simultaneous to a very high accuracy, then you would see that air drag is negligible here. Yes, theoretically speaking, there would be a tiny difference in the time they landed, even in a perfect world. The word "negligible" here means "small enough to be neglected", not "false".
There are three other factors which were not discussed in answering the question about which ball hits the ground first. 1. Aerodynamics, and this factor has been largely mitigated by the two balls having similar geometry and being of substantial mass. Try this with basketball and a latex balloon of the same size and you’ll see the difference.
Net force = mass x acceleration. Gravitational force (aka weight) = mass x gravitational acceleration. Weight divided by mass = gravitational acceleration -> mass doesn't matter when it comes to how fast something accelerates in free fall (acceleration is the change in speed of an object).
Same thing. The balls will experience the same gravitational acceleration, and as long as air resistance is not different for the two balls (with these, their surfaces are similar enough that it's going to be practically identical) they will accelerate towards the ground at the same rate, and hit the ground at the same time. The heavier ball has more force on it, but it also has more inertia - these balance out exactly, so it doesn't fall any faster than the light ball.
I understand what you are pointing out. But the black ball will fall faster because a smaller percentage of the gravitational force is being used to fight the drag. I challenge you to do the same experiment from a great hight. Like off a cliff. Because the air drag is roughly the same, the black ball will hit the ground first. The effect is too small from 6 or 7 ft to notice. That said. I love your videos. As vsauce said "they are superb."
greg palmer Right in theory, wrong in principle. The reason the black ball has a higher terminal velocity is because it has a greater gravitational force compared to the other ball in this case Mg>mg. Given all the other properties of the two balls are the same friction, size etc then the drag force of both will increase proportionally. However because the Black one is heavier it takes longer for the drag force to equal the weight and so it is able to accelerate for longer before reaching terminal velocity. This is why heavier objects fall faster over long distance they have a larger weight(Force) fighting the drag not less.
TheJamsplat Wrong in reply. He is BOTH correct in theory AND in principal. Regardless of the height that the spheres are dropped from, when there are two spheres with identical drag coefficients and differing masses the sphere with the greater mass will hit the ground first because, as you stated, it will " accelerate for longer before reaching terminal velocity". That is to say, the sphere with greater mass will CONTINUE to accelerate at a RELATIVELY greater rate when compared to the sphere with lesser mass " because the Black one is heavier [and] it takes longer for the drag force to equal the weight and so [that] it is able to accelerate for longer before reaching terminal velocity." So both in Theory and in Practice the black ball will hit the ground first. Now if this experiment were duplicated in a vacuum then there would be no difference...
His theory was the black ball would hit the ground first which was correct theory. The principle he used to explain this was nonsense and confusing anyway.
(I am just guessing here and didn't really do research before this so sorry if I sound stupid) I think you are correct. Like they said, the black ball has more inertia so it needs more force to make it stop or start moving but the force of gravity is greater on it countering this fact. Since both balls are mostly the same shape, I assume the force of drag will be the same on both. The black ball needs more force to slow it than the basketball, so that means that it will fall faster.
+Küsh_Lord The one with greater mass will hit first, it has a more significant pull against the earth. Although the difference would be nearly immeasurable, It is calculable. You just need to consider both their radial distance from each other and their differences in mass. Like say if one ball was say 2 billion kilo-grammes, and the other was 100 kilo-grammes, and they were about 2000 miles apart, the more massive ball would hit far sooner than the other.
Can someone answer me a question? I know that all objects fall to Earth with equal acceleration, but isn't this only because these objects have negligible mass compared to Earth? I could have a hypothetical sphere with a mass that represented a significant percentage of Earth's, and another sphere of equal volume with the mass of a basketball, would there be a difference?
+Tom Sigsworth according to newtons proposition in regards to gravitational forces, published in his Philosophiæ Naturalis Principia Mathematica, the mass of both objects is significant. Since those bodies also attract the planet toward themselves, relative to the planet the objects are accelerating at uneven rates, assuming they are not in line with each other. So the one with greater mass, like say a moon versus a basketball, would impact the planet first. With more similarly massed objects like in the video, the difference is so small it isn't noticeable in the experimentation environment, but really does exist.
0:48 The Asian guy is technically right, the force of gravity is stronger on the black ball. Unfortunately it’s acceleration we’re interested in, not force.
No, because the coefficient friction of both balls would be the same, meaning for the same speed, the force pulling down on the lighter ball would have greater difficulty overcoming the force of friction. Think of this in a more dramatic example. A ball filled with lead vs the same size ball filled with air. The ball filled with lead would reach a much higher terminal velocity than the ball filled with air.
All the subjects claimed that the dramatically (about 10 times) heavier, similarly sized and shaped black ball would hit the ground first. They were right. Having not lived their lives in a vacuum, the interviewees all know that if you drop items of different weight and equal size and shape at the same time, the item with greater weight will descend more quickly in still air. The interviewees answered accordingly and they were right.
49metal You've missed the point. From the height they were dropped, drag was insignificant. The fact that he probably did not drop them at precisely the same time would have just as much of an impact on which ball hits first as the drag does in this scenario. The point is - even if they did not hit the ground at precisely the same time, the reason had nothing to do with gravity. That's the point. Gravity accelerates all objects at the same height at the same rate regardless of their mass. This video sufficiently shows this.
So, you say that whether the balls hit the ground at the same time or not has (1) nothing to do with gravity and that (2) drag is inconsequential too. Your point therefore is that because his method is so careless it makes both gravity and drag irrelevant to answering the question. I do not think I missed the point. I think claiming his question has nothing to do with gravity or drag really does miss the point--unless the point is to demonstrate that his respondents don't recognize that the sloppy method of the experiment makes the question unanswerable. I think his question was intended to assume that the balls were dropped simultaneously. I think this is implicit enough in how he puts his question. You seem to think that he also wants his respondents to assume the balls are falling in a vacuum rather than in still air. I am suggesting that, under the circumstances, his respondents assume precisely the former, which is what I would have done and probably most engineering students would have done. Thus, he asks his respondents a question. Drag is only insignificant to this question when a vacuum is assumed and if he wants one to assume a vacuum he should say so.
49metal I said that IF........IF the balls did NOT hit the ground at the same time, it would have nothing to do with gravity. Meaning that gravity alone accelerates objects at the same rate. The video is clearly addressing gravitation, in which case drag is ignored. He has several videos that address this, and it is clear that he is addressing the misconception that heavier objects accelerate faster because of gravity. He is a physicist. If he is asserting that the objects fall at the same rate, then he is ignoring drag. It is not necessary that it be explicitly stated.....and even if drag is not being ignored.....in THIS scenario of two sufficiently massive balls being dropped from 2 meters high, drag is insignificant with respect to the general misconception regarding gravity. In other words, they fall at near enough the same rate that it is plainly obvious that any discrepancies can be blamed on variables OTHER THAN gravity. Hence the point gets across, and drag is insignificant.
Yes, he is ignoring drag--not that ignoring drag is necessarily what a good physicist would do. He can make a point by ignoring drag and make a point by not ignoring drag. My point is that the video is mainly about the notions of common people in this regard. The video suggests that people should answer his question by saying the objects should hit the ground simultaneously. He might expect us, his erudite viewers, to "know better"(?) but he has no business expecting his human subjects to infer that drag should be ignored. A correct answer from them, therefore, should take drag into account. Clearly, some of them are attempting to do that and they are not wrong for doing so.
49metal I very seriously doubt that they are consiously taking drag into account. Drag is always ignored when discussing the fundamentals of gravity. Have you ever seen a physics text book?
Great little demonstration. My students liked seeing others get it wrong on the video and they refused the video was real, so we had to do the experiment ourselves.
This isn't taking into account air resistance and associated terminal velocity. If the drop height were significant enough (off of a tall building), the dark ball will hit first due to it having a higher terminal velocity. In a vacuum they would both hit at the same time.
Come on I learnt this in primary school if both objects have the same Surfis area that will fall at the same speed but if the Surfis area is different like a pice of paper and a penny the pent will hit the ground first because it has less drag being put apron it than the paper
ash craft First of all, this video is ignoring drag. Second of all, if you are going to consider drag, surface area is one of several factors that come into play. If two objects have the same surface area, the more massive one will fall faster.
Willoughby Krenzteinburg The point is not about drag, but about inercia and acceleration. None of this drag concern will be necessary in a vacuum and the principles here explained would then apply at any hight. But sure, the more inercia the longer you can fight atmosferic drag, causing a difference in final speed.
When you are talking about FALLING bodies, the force of drag will depend on mass. While mass is not a factor in the force of drag itself, it CERTAINLY is a factor in determining the resulting acceleration. In other words, a certain force of drag will slow down a less massive object more than a more massive one. The result is the more massive falling faster, and thus experiencing a greater force of drag (given all other properties are the same). So weight DOES have an effect on drag here.
a simpler way of thinking of it is that if you had three apples dropped them simultaniously they would all hit the ground at the same time. if you were to attach two of them with a string they would still hit the ground at he same time. as you shorten the string it becomes apparent that the two apples are becoming one but they still fall at the same rate eventually you realize you could smash these to apples together to make a sticky mess and there would be no reason for the apples to go faster.
In a vacuum, they would hit at the same time. In air, the heavier one will land first. It will not be because the air resistance is greater on the lighter ball (because air resistance is actually stronger on the heavier object since it is falling faster through the air), it will be because the force of drag has a greater effect on the lighter (less massive) object, so it counters the acceleration due to gravity more than the greater force of drag on the heavier (more massive) object.
In the video, the balls drop at the same rate, but in more extreme circumstances, it does affect it. Drag force Fd=(1/2)pv^2CA. P is density of fluid, v is speed, A is cross-sectional area, C is drag coefficient. This opposes the weight force, so net force=mg-(1/2)pv^2CA. Total force is ma, a being net acceleration. so ma=mg-(1/2)pv^2CA. Divide out the mass and a=g-(1/2)pv^2CA/m. As m increases, negative acceleration due to drag decreases.
The medicine ball WILL hit the ground first! It has an identical shape and surface compared to the basketball, and a greater mass. The air friction from the falling movement will slow the basketball more. (dropping from only about 6 ft, the time to drop will differ by milliseconds only, of course)
+Marvin Kitfox But the air drag is proportional to the object's density, so all other things being equal, the deceleration from the air drag will be the same.
Weight has no effect on drag. If you mean that the drag of the basketball is higher (thus the basketball dropping slower) because of the basketball being bigger (and so having a higher drag coefficient) than the medicine ball, in that case you are correct.
krapotkin71 terminal velocity is the maximum speed and object can reach being accelated by gravity and can be calculated with Sqrt(gm/k) So the mass does matter In a vacuüm all object fall at the same rate no matter what but with air resistance it's a different story
You are not thinking about air friction (also called drag). As the object falls faster, the air causes a stronger upward force. There is a certain speed at which these two forces equalize each other in magnitude, but if at that same speed the object had more mass, the downward force (F=m*a) would be larger than the upward force (F=(1/2)*ρ*v^2*Cd*A) , which doesn't depend on mass, so it would therefore need a greater speed to equalize the downward force in magnitude.
The acceleration due to gravity is the same for all falling bodies given that they are dropped from the same location and height, BUT the more mass an object has, the more force it takes to accelerate it at the same rate as a lesser massive body because of inertia. Inertia is a body's resistance to acceleration, and it is proportional to mass (more mass = more inertia). So, the more massive a body is, the greater the force of gravity is on that body, but the resulting accelerations are the same.
It all depends on the perspective, like, for instance they fall to the Earth with the same velocity and acceleration, but theoretically the denser ball will land first as it has more pull on the Earth than the light ball does. Which means they fall at the same speed, but they land at different times
Yes, but it should be intuitive that there isn't enough air resistance at 6 feet or so for either object to reach terminal velocity. Take air out of the picture entirely, and there is no terminal velocity, just bad news for the guy who drops a medicine ball on his foot from a mile up.
That is only because the sheet of paper is not strong enough and will get loss in wind streams. But if it was thick enough (plastified or something like it) it would hit the ground at the exact same time. If you drop the paper and the gold sheet in an airless environnement they would hit the ground at the same time.
An even better experiment would be to have a feather and a book. You ask which one drops to the ground first while holding both in separate hands. Most people will be correct when they say that the book will reach the ground before the feather. Then you place the feather on top of the book and ask the same question. What happens is that since the book shields the feather from the influence of air-resistance, the feather and book will drop at the same rate.
Air friction gets falling objects not to fall so quickly when falling at high speeds. This upward force depends on the area of contact and the velocity. When you reach a certain speed, it gets high enough to equal the gravity force's magnitude (F=m*a), but with opposite direction (think: feathers). Note that gravity's force depends on the mass, but not the air friction one! See how skydivers go faster when having a more compact shape (less contact area w/ air). Wiki: terminal velocity and drag.
Technically black ball is still landing first due to air friction. Black ball is say 5 times heavier and is being affected by 5 times higher force but air resistance due to same shape and size is the same for both balls and as black one has 5 times as much inertia air resistance affects it 5 times less. At this height the difference is noticeable of course but would be noticable from higher as terminal velocity of same shape and higher density object is higher.
In fact, you should read up on terminal velocity. This is the speed where an objects stops accelerating because the force of gravity has been fully countered by the force of drag. As you should know, the force of gravity is also known as weight. A heavier object requires more drag force to counter its own weight, and this would mean it needs to fall faster through the medium - increasing its drag. If a heavier body has a higher terminal velocity, then it will also experience a greater F(drag)
@kire271MK You misunderstood the moon video. According to that video, the earth pulls on the medicine ball with the same force the medicine ball pulls on the earth. Also, the earth pulls on the basketball with the same force the basketball pulls on the earth. However, this doesn't mean that the force the that earth pulls with is the same for both the medicine ball and the basketball.
its a short distance and there is air. which not one person mentioned. both fall at the same rate. they even did it on the moon and dropped a rock hammer and a feather at the same time and both hit at the same time. has nothing to do with inertia. a better one would be to have a big ramp with a wheel type device or ring and a solid cube of the same weight. The solid cube will hit first
@Arlemagne I'm not veritasium, but yes, you are right. Because wind resistance is determined by the shape and size, not the mass of an object, up-force is the same for both balls, but the force of gravity is larger on the bigger ball, making that fall faster. The two would only hit the ground at the same time in a vacuum.
it actually doesn't, because they're the same size and shape they both interact with the air in the same way, therefore it wont effect the outcome.( they're equally aerodynamic) You only need the vacuum if they're completely different objects, like a feather and a hammer, because the feathers mass is so spread out it falls slowly, if you don't believe me just take a feather and a needle (about the same weight of course) and drop them, the needle hits first because its more aerodynamic
Let's forget about the texture for now. The heavier ball has greater terminal velocity if their surface area is the same. The wind resistance has to add up until it exerts enough force to the ball for it to stop accelerating. Denser objects have greater terminal velocities, given that the shape of the objects in question is the same. This phenomenon cannot be observed from this experiment though because neither of the balls got even close to their terminal velocities.
@IceTorch051 It's due to the feather having resistance against air (similar to a piece of paper or a skydiver outstretching their arms). If these two objects were dropped at the same time in space (or another vacuum), they will fall at exactly the same speed.
The idea that the heavier ball would land first is technically correct. However, the distance the balls need to travel to reach their terminal velocity is much longer than the distance they fall in this video. Therefore, they accelerate at the same rate over the same distance meaning it takes the same amount of time. I think one person in this video said the terminal velocity thing. All in all it was a very good video for people who are just learning basic physics.
The force of gravity is greater, according to the equation, F= mass x acceleration. Since the acceleration caused by gravity is constant (9.8ms^-2), and the mass of the medicine ball is greater, this means that the force of gravity on the medicine ball is greater as well. However, when air resistance is considered, the balls would not fall at the same rate, going by the same equation (F=ma).
I know the correct answer, but I have never completely understood it. The balls travel through air, and air is a fluid. In fluids, objects with a greater density fall or sink, and objects with a lesser density rise or float. This also means that the denser the object, the faster it will fall. It happens this way in water, why not in air?
It depends what you mean by "there." The medicine ball would reach the 500 kg ball first, but only because the 500 kg ball would have move towards the medicine ball (this is because of Newton's third law, both masses are attracted to each other). If however the 500 kg ball was fixed (ie not moving) then both the medicine ball and the basketball would reach it at the exact same time.
He is right. The magnitude of the drag force itself does not depend on mass, but how that force will affect an object certainly depends on its mass (a=F/m). Are you saying that if I were to make a foam mold of a bowling ball (an exact replica), that the foam ball, and the actual bowling ball will fall at the same rate because its only the size that matters. Why don't we just see what the equation for terminal velocity says... V(t) = √(2gm/pAC) It appears mass is relevant, doesn't it? Yep
Which would hit the ground first? A bullet shot from a gun aimed horizontal, three feet above the ground, or a bullet dropped from three feet above the ground at exactly the same time the bullet was fired from the gun?
They would both hit the ground at the same time, just because there's an explosive force pushing the bullet, it wouldn't provide a counter force to gravity, just means it would be incredibly hard to measure (pretty hard to measure when a speeding bullet hits the ground at a speed of 343 m/s)
Except those are examples of objects where red herrings like air resistance and buoyancy get in the way from the real issue. The idea is to see what factors govern a mass's nature for falling in general, when only the fundamental factors that govern falling are at play. Air drag and buoyancy exist on our planet and do govern falling, but only secondarily, and are something we'd prefer to remove to keep the calculation simple.
@@carultch That is correct, but I don't think air drag and buoyancy are really "red herrings", nor is gravity the only "real issue" involved. In this test, within the parametres of the drop height and the mass of each object, aerostatic lift and aerodynamic drag do not really become relevant factors - or at least it is very difficult to tell any difference with human senses. So we can say that in this example, the two objects fall at approximately the same acceleration and hit the ground at approximately the same time, and only gravity matters. In a hypothetical "physics exercise" situation where atmosphere is entirely ignored, this assumption would be true for pretty much all objects that have significantly smaller mass than the planet itself. What I wanted to highlight is that generalizations like this can lead to dangerous misconceptions and confusion about situations where real world objects no longer behave like the simplified generalization would predict. This is why I would prefer to see it made it very clear in the video that this generalization is only accurate in situations where the effects of air drag and buoyancy are very small relative to gravity. The reason why I suggested a test with very different objects was specifically to illustrate that this generalization is not something we can always rely on, and that in some cases other forces become just as relevant as gravity for correctly predicting how an object will behave when you let go of it.
not exactly, the lighter one would start to accelerate more slowly a long time before reaching it maximum velocity, and the heavier one too, but it would take longer. Actually, even in this video, the both of them lost a bit of energy to air resistance (which means if we did it in a lab, the medecine ball would fall at least a few microseconds before the basketball). But it's such a small amount of energy it's negligible.
i think most people get confused and think it only works in a vacuum because you generally think of a heavier object as, for example a rock, and the lighter, say, a feather, or a piece of paper, 2 different masses with different forms, and generally light objects (paper, feathers etc.) really feel the resistant of air, to show its not the lack of mass that slows it down, put a piece of paper on a phone book and drop them, they wont fall slowly.
Yeah... I did this experiment with a cantaloupe and an orange. I was about 4 feet off the ground.... The truth is that the acceleration of similar shaped objects under Earth's gravity is the same until one object reaches terminal velocity, only then will the object of greater mass continue to accelerate.... Now, different shaped objects, however, will accelerate differently because of air resistance. An object shaped like a bullet may drop faster than a spherical object, or a smooth sphere may accelerate differently than a golf ball shaped object, but this difference may be to small to detect with the naked eye.
I'm not sure about that... I thought it would rather be about the acceleration due to gravity being constant for all objects. It does not matter how heavy the item is if you're considering acceleration only. The only thing changing due to mass, assuming constant surface area, is the terminal velocity it can reach. Since, within the time frame of reaching the ground at that height does not give the balls enough time to reach their terminal velocity, both balls hit the ground at the same time.
Not their heaviness, their density. In a vacuum there's no air resistance to mess with our experiments and the gravitational interaction between earth and a heavy rock makes the rock accelerate towards earth's center of mass in the same way as it does to a feather. The reason for this is as Veritasium has explained in his other videos, inertia.
Some of them are right though, the Black one in theory should have a greater terminal velocity because the force of gravity is more significant vs the air resistance than the lighter ball.
I was arguing with a friend of mine about this not to long ago. He said something rediculus, and our sience teacher argeed with it, I hated that. He said because the gravitational pull of the small falling objects was so small, it didn't exist at all. I said something slightly less ridiculus, but noone agreed. I totaly forgot what I said, sorry. Now you explained it, in a way that actually makes sence! Thank you! (Sorry for my horrible English, I'm Dutch, and 14).
This video is appropriate for the height from which the objects are dropped. Of course from 100m air resistance becomes significant. So a result that applies to one situation does not necessarily apply to others. In science we must be careful about generalising our findings to different situations where our assumptions may no longer be valid.
Hey
do it on the moon
Yeah
Yeah…
@Pal mernoudaz. It has been done on moon by astronauts just not with basketballs. One object was a feather and other can’t remember for sure but much heavier object like a hammer. And they hit at same time. They also have huge chambers on earth which they can suck all the air out of and dropped objects from much greater height with same result.
no, it really is true. Do the experiment. You can see in this video that they certainly do not land half a second apart. Things like not being dropped perfectly simultaneously and from the exact same height play a bigger role in this case than air resistance.
Hello Veritasium you are my inspiration
Ok I agree this is true 😂
Hey Veritasium!
Never gonna give you up
Never gonna let you down
light and gravity both have their influence propagate at the same speed. This suggests something fundamental about the fabric of space-time.
v = root(2gh)....independent of mass. The case is closed ;)
Bruh thats crazy
@@rajarshimukherjee4844 F=Ma anf F=GM1M2/r^2 Equate the values of F and The Mass of the ball will cancel out leaving the mass of the Earth M2. Therefore the Force acting on both balls is different but they cancel there own mass as heavier ball needs more force to attain that same acceleration.
Who else thought that nut shot was so unexpected yet hilarious? hahaha
Everyone under 14 probably.
Just glad he wasn't hurt so badly.
FALSE. The pink ball hit the ground first.
+R Cain And two balls shot up momentarily. :)
FALSE. The pink ball hit the *balls* _first_.
it wasn't even a ball
Omg so much comments in here....🤣😁
🤣🤣🤣🤣 Oh he would have been in very pain while throwing down the balls. Did you saw his gesture?
😂😂😂🤣😂🤣😂
These are university students. Are you kidding me.
+don gerkin they must be kardashian fans.
air will make the basketball go up!.....are you fckin kidin me??.....
+don gerkin
The best of the best. This is why i think people should stop studying their dumbass social sciences and get a degree in things that aren't still points of contention.
And I can't even get into Uni
at least this means that anyone can easily get into uni
HE LOOKS SO YOUNG HERE HAHAHA
And you too
And you too
covid19
It's the beard
I watched him the first time this year. I don't even recognize him. I thought this is just a random kid he hired to shoot a video
Gravitation is an interesting concept. Taking account Newton's third law, when you drop something the only thing moving is not the object you dropped but also the Earth is accelerating towards your falling object. The amount of the Earth's movement is immeasurably tiny because of the humongous inertia of the Earth but it's indeed possible to calculate. Also the Moon does not circle the Earth, rather they both circle around their combined center of mass which happens to be inside of the Earth.
CORRECT
In a vacuum, they will both fall at the same rate and hit the ground at the same time. But if dropped from a higher distance outside, the black one will hit the ground first because the lighter basketball will succumb to air resistance.
+Odspotikins True, the magnitude of the force of air resistance would be the same for each, but the basketball would decelerate more quickly than the medicine ball since it has less mass. The medicine ball would still hit the ground first.
exactly
+centersnare32 not quite since they are both the same shape
However, if dropped separately, even in a vacuum, although the gravitational force from earth to each ball divided by their inertia is exactly the same, each ball exerts a (very, very tiny) gravitational force on the earth, accelerating the earth to the ball. The gravitational pull of the more massive ball will give the earth more weight with respect to the ball than the less massive ball would. So, the time for the more massive ball and earth to collide from a set distance (from an outside perspective, because the inertia of the earth is much greater than that of either ball we would just interpret the event as the ball falling to earth) would be less than that of the less massive ball.
+Niko Yochum Same shape, same resisting force, but the bowling ball have more inercia, so it will "feel" less aceleration.A=F/M aceleration is the force divide by the mass, if the force is the same, the one with more mass got less decelaration.
I'm glad I watch these videos of yours where I already know the answer, because I didn't realise until the end that I didn't know WHY. Thanks for explaining the mass/inertia bit.
Where do you find these people that dont know basic high school physics?
I mean come on, this is one of the first things you learn...
Not everyone takes high school physics, hell a lot of high schools don't even offer physics.
ParaditeRs
Mm and not every1 finish school either.. or don't pay attention at all/buy their way to the next grade, or crap school or a giving teacher & then not watch interesting science videos like these on youtube as well
ParaditeRs But this is a COLLEGE.
Moniker Peters The original poster mentioned high school physics in particular.
Magno313 some people never took physics like me or never paid attention
"I'm gonna put my money on the black fella"
I lost my shit, didn't hear the rest of the vid.
You're telling me he's been doing this kind of stuff for at least 13 years! I guess it's better than working in a factory for 13 years.
@kire271MK First, let me say that all discussion of terminal velocity and air resistance is irrelevant to this experiment because the balls clearly aren't falling far enough for air effects to be noticeable. Second, the gravitational force on the balls is NOT the same. When you pick up the medicine ball, you notice is has a much greater attraction to the Earth. Yes, the resulting accelerations are the same, and that is because the inertia of the medicine ball is proportionately greater.
Bug
"Not enough for air to be noticeable" is not the same thing as "not enough for air to matter" It does still matter, and the medicine ball WILL still hit first all other things being equal, whether your poorly set up experiment is able to allow it to be noticed from the noisy muscle inconsistencies or not. Which normally wouldn't be a big deal, except for when you go around telling students that they're wrong for guessing that when they are not wrong for guessing that......
Veritasium don't know if you'll see this reply, but just wanted to say you looked so young, like literally so different 10 years ago that I had to make sure it was you, Derek and not somebody else. It was only after looking at the fact that the video was posted 10 years ago and your voice and little face similarity that I could tell that it was you.
Acceleration is independent of mass, therefore if you ignore air resistance AKA drag force, they accelerate at the same rate and thus hit the ground simultaneously.
Factoring in air resistance, two extra facts are relevant: drag force is dependent on the velocity of the object, and a lighter object has a smaller terminal velocity. Until both objects accelerate past the lighter object's terminal velocity, they will be "dragged" the same amount (which changes equally for both as they accelerate), meaning they still accelerate at the same rate and hit the ground at the exact same time. But if the lighter object hits its terminal velocity, gravity and drag balance out and it stops accelerating.
So if and only if both balls fall long enough to allow their speeds to accelerate pass the basketball's terminal velocity, the medicine ball will hit the ground first.
*Gravitational acceleration is independent of mass, not all acceleration.
Correct, sorry just meant acceleration in this problem
What about buoyant force? It depends on thickness so...
1betrieb1 the buoyancy of the objects (in what I am assuming is air) is like saying the force of air against the objects, which equates to the friction, meaning it is neglected... I think. I am unfamiliar with buoyancy, for I am only a highschool graduate :)
Brenton Kludt No i think it would make a (really small) diffrence.
If we'd talk in my mother tounge i could explain it, but in english it's hard^^
1:29 shot from Messi. What accuracy
10 years later and you're production quality has improved and your subscribers have skyrocketed, but your humbleness has stayed the same. Here's to more years of success to this channel.
My thoughts on this, since I learned of this in elementary school science, is that the aerodynamics of the object have more of an effect on its acceleration than any mass/weight. Of course, this goes right out the window in a perfect vacuum. (Thank you, Bill Nye.) I've always had issues with this demonstration for this reason. Cool videos, but man o man, am I glad you got better at this the further this channel's gone on.
"You can't corrupt me"
How far this channel has come,... A true inspiration! :)
1:47 Damn these guys predicted VAR
2. Buoyancy which depends not on the mass but the density of the balls.
3. Its not just the ball falling towards the earth but the earth is also falling towards the ball. This factor would make the heavier ball hit the earth first since the earth would be “falling” towards the ball a little faster.
When I was recreating this with random objects decided to drop a can of bug spray and it broke the cap so when I picked it up it sprayed directly in my eyes...
And this is a university? For real?
I know right. I knew this since Grade School.
ok, nobody learns physics at first grade. you most likely learned it at the age of 12 (unless you taught yourself at home).
or maybe wherever you're from you learn it early. how should I know?
12 year olds are in grade school, but this is pretty elementary stuff.
Sigi Baes an AMERICAN univeristy, there's a difference...
Universities teach humanities and arts too. Physics not requires in BAs
Once I had to convince, my friend how objects fall in air (he just insisted on misunderstood school half knowledge that all things fall the same). I let two cans of Coke falling down from the tenth floor at the same time. One can was full and the other was empty (opening closed). The full can was the first to reach the floor by a clear intervall. And it bursts completely. The empty can had no scratches.
For better understanding it helped my friend to imagine two sinking balls in honey-like fluid, one very heavy weighted and one distinctly lighter. But it was a real hard concept changing process for him.
The heavier ball reaches a higher sinking velocity in the end (as one of the girls in the video said). Both balls with clearly different gravity forces accelerate until air friction compensates these different forces (so the heavier ball gets more time of acceleration until compensation. And the phenomenon that the quantum of force of air resistance depends on the speed, has been experienced by everyone who has ever held a hand out of an accelerating car)...
But to be correct, the real question was: which of the two balls in the video lands first from a height of about 2 m? I don't think, that the lighter ball reaches its end velocity within this short distance and so it most likely keeps up with the heavier one (empirical evidence pending).
Inertia and gravitational force balance each other. So they fall on the ground at the same time. Air resistance can be negligible, they are almost in the same conditions (material, shape)
I used to think Science was so boring that even the sun might forget to rise. But thx to your videos, Science is not that boring
The best part of this video was the girl that thought the basketball might actually go up because it had air in it. I had to rewind it to make sure I actually heard that correctly.
It works only because the balls are dropped from a couple of meter. Drop them from 200 meters and the black one will reach the ground first.
The force due to gravity is different but the resulting acceleration the same.
The force due to air resistance is the same but it generates a higher acceleration on the basket ball.
But to have air resistance to actually work you need a longer drop.
I'm not sure inertia has anything to do with gravitational acceleration.
+rikirikibis Both the gravitational acceleration and inertia are relative to mass, so increasing the mass increases both, causing no difference in the rate of change of velocity. In an ideal universe, at least.
Maybe so, but that was before the internet was invented and people decided they didn't need to know anything any more! (It was Galileo Galilei that did the experiment).
Not true, every object that is linked with earth's gravity will drop at the same rate. This however is changed by the air resistant. This has been tested many times before. Mass does not play a roll on what gravity pulls in faster, because it can't.
You are all saying the answer is obvious but it's not. I totally understand the reason but this is mostly counterintuitive. Almost every human thinks something lighter would take more time to reach the ground because most things that are lighter like a balloon, plastic bag, feathers take longer than let's say a tennis ball or a jacket. Because of this, we would quickly draw conclusion and associate an object's weight with how fast it would fall so it makes sense that almost everyone is wrong in this video. My point is, the most intuitive way to think is a feather is lighter than a ball, a feather takes longer to hit the ground than a ball, therefore, a lighter object takes longer to hit the ground than a heavier object(which is wrong but that's the most intuitive way). an average person wouldn't pay that much attention to something like air resistance and inertia.
year: 2011
1:48 two guys doing the var symbol
THEYRE TIME TRAVELLERS MAN
Yoo, I didnt notice
Uhh no it's used in cricket for years
2:04
"Very close, probably just a bee's dick in it"
Classic Aussie hahah
You should do a video on 2 tennis balls, which one will hit the ground faster and throw one of them
Also, being the height of the fall is 'very very high', both balls would probably reach their terminal velocities, and that speed is higher for the more massive object. Terminal velocity is when the force of drag is equal to the force of gravity. Since the force of gravity is greater on the more massive ball, then the force of drag required to counter gravity is also greater. Since the objects have different masses, but are otherwise identical, the only variable that can affect drag is speed.
But steels heavier than feathers ...
The booth a kellaglam.
If you were to do the experiment in such a way that the drop was automated, perfectly similar and simultaneous to a very high accuracy, then you would see that air drag is negligible here. Yes, theoretically speaking, there would be a tiny difference in the time they landed, even in a perfect world. The word "negligible" here means "small enough to be neglected", not "false".
2:19 "break more air" = air resistance (kinda)
So not entirely wrong, I'd say...
Entirely wrong, I'd say, because it doesn't have to break more air. The air resistance for both balls is the same as they have the same shape
There are three other factors which were not discussed in answering the question about which ball hits the ground first.
1. Aerodynamics, and this factor has been largely mitigated by the two balls having similar geometry and being of substantial mass. Try this with basketball and a latex balloon of the same size and you’ll see the difference.
Love how they both asked for the 3rd umpire at 1:47
Net force = mass x acceleration.
Gravitational force (aka weight) = mass x gravitational acceleration.
Weight divided by mass = gravitational acceleration -> mass doesn't matter when it comes to how fast something accelerates in free fall (acceleration is the change in speed of an object).
Jesus Christ, have any of these people heard of Galileo? Have they taken a science class? Hell, they even go over this stuff in history class.
True
Same thing. The balls will experience the same gravitational acceleration, and as long as air resistance is not different for the two balls (with these, their surfaces are similar enough that it's going to be practically identical) they will accelerate towards the ground at the same rate, and hit the ground at the same time.
The heavier ball has more force on it, but it also has more inertia - these balance out exactly, so it doesn't fall any faster than the light ball.
I understand what you are pointing out. But the black ball will fall faster because a smaller percentage of the gravitational force is being used to fight the drag.
I challenge you to do the same experiment from a great hight. Like off a cliff. Because the air drag is roughly the same, the black ball will hit the ground first. The effect is too small from 6 or 7 ft to notice.
That said. I love your videos. As vsauce said "they are superb."
greg palmer Right in theory, wrong in principle. The reason the black ball has a higher terminal velocity is because it has a greater gravitational force compared to the other ball in this case Mg>mg. Given all the other properties of the two balls are the same friction, size etc then the drag force of both will increase proportionally. However because the Black one is heavier it takes longer for the drag force to equal the weight and so it is able to accelerate for longer before reaching terminal velocity. This is why heavier objects fall faster over long distance they have a larger weight(Force) fighting the drag not less.
TheJamsplat
Wrong in reply. He is BOTH correct in theory AND in principal. Regardless of the height that the spheres are dropped from, when there are two spheres with identical drag coefficients and differing masses the sphere with the greater mass will hit the ground first because, as you stated, it will " accelerate for longer before reaching terminal velocity". That is to say, the sphere with greater mass will CONTINUE to accelerate at a RELATIVELY greater rate when compared to the sphere with lesser mass " because the Black one is heavier [and] it takes longer for the drag force to equal the weight and so [that] it is able to accelerate for longer before reaching terminal velocity."
So both in Theory and in Practice the black ball will hit the ground first.
Now if this experiment were duplicated in a vacuum then there would be no difference...
His theory was the black ball would hit the ground first which was correct theory. The principle he used to explain this was nonsense and confusing anyway.
Yes, it could have been explained more clearly.
(I am just guessing here and didn't really do research before this so sorry if I sound stupid) I think you are correct. Like they said, the black ball has more inertia so it needs more force to make it stop or start moving but the force of gravity is greater on it countering this fact. Since both balls are mostly the same shape, I assume the force of drag will be the same on both. The black ball needs more force to slow it than the basketball, so that means that it will fall faster.
The Che Guevara/Einstein T-shirt is absolutely superb :O
same result, for any arbitrary distance r that is r
Both of them due to the fact that both of them experience the same acceleration (about 9.81m/s^2)
+Küsh_Lord indeed y = h0 - gt^2
+Küsh_Lord The one with greater mass will hit first, it has a more significant pull against the earth. Although the difference would be nearly immeasurable, It is calculable. You just need to consider both their radial distance from each other and their differences in mass. Like say if one ball was say 2 billion kilo-grammes, and the other was 100 kilo-grammes, and they were about 2000 miles apart, the more massive ball would hit far sooner than the other.
Newton kinda figured this one out a long time ago.
Can someone answer me a question? I know that all objects fall to Earth with equal acceleration, but isn't this only because these objects have negligible mass compared to Earth? I could have a hypothetical sphere with a mass that represented a significant percentage of Earth's, and another sphere of equal volume with the mass of a basketball, would there be a difference?
+Tom Sigsworth according to newtons proposition in regards to gravitational forces, published in his Philosophiæ Naturalis Principia Mathematica,
the mass of both objects is significant. Since those bodies also attract the planet toward themselves, relative to the planet the objects are accelerating at uneven rates, assuming they are not in line with each other. So the one with greater mass, like say a moon versus a basketball, would impact the planet first. With more similarly massed objects like in the video, the difference is so small it isn't noticeable in the experimentation environment, but really does exist.
0:48 The Asian guy is technically right, the force of gravity is stronger on the black ball. Unfortunately it’s acceleration we’re interested in, not force.
@1:53 lol
Hahaha
No, because the coefficient friction of both balls would be the same, meaning for the same speed, the force pulling down on the lighter ball would have greater difficulty overcoming the force of friction.
Think of this in a more dramatic example.
A ball filled with lead vs the same size ball filled with air.
The ball filled with lead would reach a much higher terminal velocity than the ball filled with air.
All the subjects claimed that the dramatically (about 10 times) heavier, similarly sized and shaped black ball would hit the ground first. They were right. Having not lived their lives in a vacuum, the interviewees all know that if you drop items of different weight and equal size and shape at the same time, the item with greater weight will descend more quickly in still air. The interviewees answered accordingly and they were right.
49metal You've missed the point. From the height they were dropped, drag was insignificant. The fact that he probably did not drop them at precisely the same time would have just as much of an impact on which ball hits first as the drag does in this scenario. The point is - even if they did not hit the ground at precisely the same time, the reason had nothing to do with gravity. That's the point. Gravity accelerates all objects at the same height at the same rate regardless of their mass. This video sufficiently shows this.
So, you say that whether the balls hit the ground at the same time or not has (1) nothing to do with gravity and that (2) drag is inconsequential too. Your point therefore is that because his method is so careless it makes both gravity and drag irrelevant to answering the question.
I do not think I missed the point. I think claiming his question has nothing to do with gravity or drag really does miss the point--unless the point is to demonstrate that his respondents don't recognize that the sloppy method of the experiment makes the question unanswerable.
I think his question was intended to assume that the balls were dropped simultaneously. I think this is implicit enough in how he puts his question. You seem to think that he also wants his respondents to assume the balls are falling in a vacuum rather than in still air. I am suggesting that, under the circumstances, his respondents assume precisely the former, which is what I would have done and probably most engineering students would have done.
Thus, he asks his respondents a question. Drag is only insignificant to this question when a vacuum is assumed and if he wants one to assume a vacuum he should say so.
49metal I said that IF........IF
the balls did NOT hit the ground at the same time, it would have nothing to do with gravity. Meaning that gravity alone accelerates objects at the same rate. The video is clearly addressing gravitation, in which case drag is ignored. He has several videos that address this, and it is clear that he is addressing the misconception that heavier objects accelerate faster because of gravity.
He is a physicist. If he is asserting that the objects fall at the same rate, then he is ignoring drag. It is not necessary that it be explicitly stated.....and even if drag is not being ignored.....in THIS scenario of two sufficiently massive balls being dropped from 2 meters high, drag is insignificant with respect to the general misconception regarding gravity. In other words, they fall at near enough the same rate that it is plainly obvious that any discrepancies can be blamed on variables OTHER THAN gravity. Hence the point gets across, and drag is insignificant.
Yes, he is ignoring drag--not that ignoring drag is necessarily what a good physicist would do. He can make a point by ignoring drag and make a point by not ignoring drag. My point is that the video is mainly about the notions of common people in this regard. The video suggests that people should answer his question by saying the objects should hit the ground simultaneously. He might expect us, his erudite viewers, to "know better"(?) but he has no business expecting his human subjects to infer that drag should be ignored. A correct answer from them, therefore, should take drag into account. Clearly, some of them are attempting to do that and they are not wrong for doing so.
49metal I very seriously doubt that they are consiously taking drag into account.
Drag is always ignored when discussing the fundamentals of gravity. Have you ever seen a physics text book?
Great little demonstration. My students liked seeing others get it wrong on the video and they refused the video was real, so we had to do the experiment ourselves.
Oh man I recognized you only from the voice 😂😂😂,lol, who's watching this in 2017?
In 2021😐
@@will_change daaam lol
This isn't taking into account air resistance and associated terminal velocity. If the drop height were significant enough (off of a tall building), the dark ball will hit first due to it having a higher terminal velocity. In a vacuum they would both hit at the same time.
This video is more for showing just the effect of gravity and for teaching the basics. So i think it's fine.
Come on I learnt this in primary school if both objects have the same Surfis area that will fall at the same speed but if the Surfis area is different like a pice of paper and a penny the pent will hit the ground first because it has less drag being put apron it than the paper
ash craft First of all, this video is ignoring drag. Second of all, if you are going to consider drag, surface area is one of several factors that come into play. If two objects have the same surface area, the more massive one will fall faster.
Willoughby Krenzteinburg The point is not about drag, but about inercia and acceleration. None of this drag concern will be necessary in a vacuum and the principles here explained would then apply at any hight. But sure, the more inercia the longer you can fight atmosferic drag, causing a difference in final speed.
Surface area you should have learned to spell
When you are talking about FALLING bodies, the force of drag will depend on mass. While mass is not a factor in the force of drag itself, it CERTAINLY is a factor in determining the resulting acceleration. In other words, a certain force of drag will slow down a less massive object more than a more massive one. The result is the more massive falling faster, and thus experiencing a greater force of drag (given all other properties are the same). So weight DOES have an effect on drag here.
what the hell, I knew that law when I was 9...
alright, fancy pants.
@@grubbyboo8427 FORTNITE PLAYER
a simpler way of thinking of it is that if you had three apples dropped them simultaniously they would all hit the ground at the same time. if you were to attach two of them with a string they would still hit the ground at he same time. as you shorten the string it becomes apparent that the two apples are becoming one but they still fall at the same rate eventually you realize you could smash these to apples together to make a sticky mess and there would be no reason for the apples to go faster.
ok, I am 13, and I knew it all. How does people manage to live without knowing this?
Martin Mehus I knew this since I was 9 or 10.
Amar Gandhi yes, people on the street is just stupid!
How does people manage ? Learn to right
Martin Mehus I bet there are many things they know that you don't
Dylan Biggs Someone needs to learn to *write* ;)
In a vacuum, they would hit at the same time. In air, the heavier one will land first. It will not be because the air resistance is greater on the lighter ball (because air resistance is actually stronger on the heavier object since it is falling faster through the air), it will be because the force of drag has a greater effect on the lighter (less massive) object, so it counters the acceleration due to gravity more than the greater force of drag on the heavier (more massive) object.
does this university make you lose knowledge?
No it just admits anyone willing... That and we only see the real cream of the less knowledgeable crop.
They don’t teach anything but how to be pc and communist nowadays
In the video, the balls drop at the same rate, but in more extreme circumstances, it does affect it. Drag force Fd=(1/2)pv^2CA. P is density of fluid, v is speed, A is cross-sectional area, C is drag coefficient. This opposes the weight force, so net force=mg-(1/2)pv^2CA. Total force is ma, a being net acceleration. so ma=mg-(1/2)pv^2CA. Divide out the mass and a=g-(1/2)pv^2CA/m. As m increases, negative acceleration due to drag decreases.
The medicine ball WILL hit the ground first!
It has an identical shape and surface compared to the basketball, and a greater mass.
The air friction from the falling movement will slow the basketball more.
(dropping from only about 6 ft, the time to drop will differ by milliseconds only, of course)
+Marvin Kitfox
But the air drag is proportional to the object's density, so all other things being equal, the deceleration from the air drag will be the same.
Marvin Kitfox I’m not sure if mass affects drag
Weight has no effect on drag. If you mean that the drag of the basketball is higher (thus the basketball dropping slower) because of the basketball being bigger (and so having a higher drag coefficient) than the medicine ball, in that case you are correct.
If you are dropping it from high enough, the basketball will reach have a lower terminal velocity and thus the medical ball will fall first.
you are aware that terminal velocity IS gravity right?
krapotkin71
That statement doesn't even make sense.
krapotkin71 terminal velocity is the maximum speed and object can reach being accelated by gravity and can be calculated with
Sqrt(gm/k)
So the mass does matter
In a vacuüm all object fall at the same rate no matter what but with air resistance it's a different story
Free fall is inertial.
Stfu
You are not thinking about air friction (also called drag). As the object falls faster, the air causes a stronger upward force. There is a certain speed at which these two forces equalize each other in magnitude, but if at that same speed the object had more mass, the downward force (F=m*a) would be larger than the upward force (F=(1/2)*ρ*v^2*Cd*A) , which doesn't depend on mass, so it would therefore need a greater speed to equalize the downward force in magnitude.
The acceleration due to gravity is the same for all falling bodies given that they are dropped from the same location and height, BUT the more mass an object has, the more force it takes to accelerate it at the same rate as a lesser massive body because of inertia. Inertia is a body's resistance to acceleration, and it is proportional to mass (more mass = more inertia). So, the more massive a body is, the greater the force of gravity is on that body, but the resulting accelerations are the same.
It all depends on the perspective, like, for instance they fall to the Earth with the same velocity and acceleration, but theoretically the denser ball will land first as it has more pull on the Earth than the light ball does. Which means they fall at the same speed, but they land at different times
That talk about terminal velocity was indeed on the right track
Yes, but it should be intuitive that there isn't enough air resistance at 6 feet or so for either object to reach terminal velocity. Take air out of the picture entirely, and there is no terminal velocity, just bad news for the guy who drops a medicine ball on his foot from a mile up.
That is only because the sheet of paper is not strong enough and will get loss in wind streams. But if it was thick enough (plastified or something like it) it would hit the ground at the exact same time. If you drop the paper and the gold sheet in an airless environnement they would hit the ground at the same time.
An even better experiment would be to have a feather and a book. You ask which one drops to the ground first while holding both in separate hands. Most people will be correct when they say that the book will reach the ground before the feather. Then you place the feather on top of the book and ask the same question. What happens is that since the book shields the feather from the influence of air-resistance, the feather and book will drop at the same rate.
Air friction gets falling objects not to fall so quickly when falling at high speeds. This upward force depends on the area of contact and the velocity. When you reach a certain speed, it gets high enough to equal the gravity force's magnitude (F=m*a), but with opposite direction (think: feathers). Note that gravity's force depends on the mass, but not the air friction one! See how skydivers go faster when having a more compact shape (less contact area w/ air). Wiki: terminal velocity and drag.
Technically black ball is still landing first due to air friction. Black ball is say 5 times heavier and is being affected by 5 times higher force but air resistance due to same shape and size is the same for both balls and as black one has 5 times as much inertia air resistance affects it 5 times less. At this height the difference is noticeable of course but would be noticable from higher as terminal velocity of same shape and higher density object is higher.
In fact, you should read up on terminal velocity. This is the speed where an objects stops accelerating because the force of gravity has been fully countered by the force of drag. As you should know, the force of gravity is also known as weight. A heavier object requires more drag force to counter its own weight, and this would mean it needs to fall faster through the medium - increasing its drag. If a heavier body has a higher terminal velocity, then it will also experience a greater F(drag)
If it's worth noting, the mass of the earth is ≈3.981 × 10^22 times that of an average human. It's significantly more massive.
Another followup video cover the subtle nuance of the answer would be fun and educational.
@kire271MK You misunderstood the moon video. According to that video, the earth pulls on the medicine ball with the same force the medicine ball pulls on the earth. Also, the earth pulls on the basketball with the same force the basketball pulls on the earth. However, this doesn't mean that the force the that earth pulls with is the same for both the medicine ball and the basketball.
its a short distance and there is air. which not one person mentioned. both fall at the same rate. they even did it on the moon and dropped a rock hammer and a feather at the same time and both hit at the same time. has nothing to do with inertia. a better one would be to have a big ramp with a wheel type device or ring and a solid cube of the same weight. The solid cube will hit first
@Arlemagne I'm not veritasium, but yes, you are right. Because wind resistance is determined by the shape and size, not the mass of an object, up-force is the same for both balls, but the force of gravity is larger on the bigger ball, making that fall faster. The two would only hit the ground at the same time in a vacuum.
it actually doesn't, because they're the same size and shape they both interact with the air in the same way, therefore it wont effect the outcome.( they're equally aerodynamic) You only need the vacuum if they're completely different objects, like a feather and a hammer, because the feathers mass is so spread out it falls slowly, if you don't believe me just take a feather and a needle (about the same weight of course) and drop them, the needle hits first because its more aerodynamic
The video is about two balls, sphere-shaped objects have low and equal air resistance and so will always fall at the same rate.
Better way to explain inertia is to make someone lie down and let someone drop a beach ball and a cannon ball on them @ the same time.
Let's forget about the texture for now. The heavier ball has greater terminal velocity if their surface area is the same. The wind resistance has to add up until it exerts enough force to the ball for it to stop accelerating. Denser objects have greater terminal velocities, given that the shape of the objects in question is the same. This phenomenon cannot be observed from this experiment though because neither of the balls got even close to their terminal velocities.
@IceTorch051 It's due to the feather having resistance against air (similar to a piece of paper or a skydiver outstretching their arms).
If these two objects were dropped at the same time in space (or another vacuum), they will fall at exactly the same speed.
The idea that the heavier ball would land first is technically correct. However, the distance the balls need to travel to reach their terminal velocity is much longer than the distance they fall in this video. Therefore, they accelerate at the same rate over the same distance meaning it takes the same amount of time. I think one person in this video said the terminal velocity thing. All in all it was a very good video for people who are just learning basic physics.
The force of gravity is greater, according to the equation, F= mass x acceleration. Since the acceleration caused by gravity is constant (9.8ms^-2), and the mass of the medicine ball is greater, this means that the force of gravity on the medicine ball is greater as well. However, when air resistance is considered, the balls would not fall at the same rate, going by the same equation (F=ma).
I know the correct answer, but I have never completely understood it. The balls travel through air, and air is a fluid. In fluids, objects with a greater density fall or sink, and objects with a lesser density rise or float. This also means that the denser the object, the faster it will fall. It happens this way in water, why not in air?
It depends what you mean by "there." The medicine ball would reach the 500 kg ball first, but only because the 500 kg ball would have move towards the medicine ball (this is because of Newton's third law, both masses are attracted to each other). If however the 500 kg ball was fixed (ie not moving) then both the medicine ball and the basketball would reach it at the exact same time.
He is right. The magnitude of the drag force itself does not depend on mass, but how that force will affect an object certainly depends on its mass (a=F/m). Are you saying that if I were to make a foam mold of a bowling ball (an exact replica), that the foam ball, and the actual bowling ball will fall at the same rate because its only the size that matters. Why don't we just see what the equation for terminal velocity says...
V(t) = √(2gm/pAC) It appears mass is relevant, doesn't it? Yep
This is a dangerous demonstration for Derek to be wearing flip flops for.
Which would hit the ground first? A bullet shot from a gun aimed horizontal, three feet above the ground, or a bullet dropped from three feet above the ground at exactly the same time the bullet was fired from the gun?
They would both hit the ground at the same time, just because there's an explosive force pushing the bullet, it wouldn't provide a counter force to gravity, just means it would be incredibly hard to measure (pretty hard to measure when a speeding bullet hits the ground at a speed of 343 m/s)
they would hit the ground at the same time, but I forgot why lol
(pretend the earth's curve is negligible)
Depends on the shape of the bulet a bit:p
You should do another test. Which one will fall the fastest, a balloon filled with air, a balloon filled with helium, or a balloon filled with water?
Except those are examples of objects where red herrings like air resistance and buoyancy get in the way from the real issue. The idea is to see what factors govern a mass's nature for falling in general, when only the fundamental factors that govern falling are at play. Air drag and buoyancy exist on our planet and do govern falling, but only secondarily, and are something we'd prefer to remove to keep the calculation simple.
@@carultch That is correct, but I don't think air drag and buoyancy are really "red herrings", nor is gravity the only "real issue" involved.
In this test, within the parametres of the drop height and the mass of each object, aerostatic lift and aerodynamic drag do not really become relevant factors - or at least it is very difficult to tell any difference with human senses. So we can say that in this example, the two objects fall at approximately the same acceleration and hit the ground at approximately the same time, and only gravity matters. In a hypothetical "physics exercise" situation where atmosphere is entirely ignored, this assumption would be true for pretty much all objects that have significantly smaller mass than the planet itself.
What I wanted to highlight is that generalizations like this can lead to dangerous misconceptions and confusion about situations where real world objects no longer behave like the simplified generalization would predict. This is why I would prefer to see it made it very clear in the video that this generalization is only accurate in situations where the effects of air drag and buoyancy are very small relative to gravity.
The reason why I suggested a test with very different objects was specifically to illustrate that this generalization is not something we can always rely on, and that in some cases other forces become just as relevant as gravity for correctly predicting how an object will behave when you let go of it.
not exactly, the lighter one would start to accelerate more slowly a long time before reaching it maximum velocity, and the heavier one too, but it would take longer. Actually, even in this video, the both of them lost a bit of energy to air resistance (which means if we did it in a lab, the medecine ball would fall at least a few microseconds before the basketball). But it's such a small amount of energy it's negligible.
i think most people get confused and think it only works in a vacuum because you generally think of a heavier object as, for example a rock, and the lighter, say, a feather, or a piece of paper, 2 different masses with different forms, and generally light objects (paper, feathers etc.) really feel the resistant of air, to show its not the lack of mass that slows it down, put a piece of paper on a phone book and drop them, they wont fall slowly.
Yeah... I did this experiment with a cantaloupe and an orange. I was about 4 feet off the ground.... The truth is that the acceleration of similar shaped objects under Earth's gravity is the same until one object reaches terminal velocity, only then will the object of greater mass continue to accelerate.... Now, different shaped objects, however, will accelerate differently because of air resistance. An object shaped like a bullet may drop faster than a spherical object, or a smooth sphere may accelerate differently than a golf ball shaped object, but this difference may be to small to detect with the naked eye.
I'm not sure about that... I thought it would rather be about the acceleration due to gravity being constant for all objects. It does not matter how heavy the item is if you're considering acceleration only. The only thing changing due to mass, assuming constant surface area, is the terminal velocity it can reach. Since, within the time frame of reaching the ground at that height does not give the balls enough time to reach their terminal velocity, both balls hit the ground at the same time.
Not their heaviness, their density. In a vacuum there's no air resistance to mess with our experiments and the gravitational interaction between earth and a heavy rock makes the rock accelerate towards earth's center of mass in the same way as it does to a feather. The reason for this is as Veritasium has explained in his other videos, inertia.
Some of them are right though, the Black one in theory should have a greater terminal velocity because the force of gravity is more significant vs the air resistance than the lighter ball.
I was arguing with a friend of mine about this not to long ago. He said something rediculus, and our sience teacher argeed with it, I hated that. He said because the gravitational pull of the small falling objects was so small, it didn't exist at all. I said something slightly less ridiculus, but noone agreed. I totaly forgot what I said, sorry. Now you explained it, in a way that actually makes sence! Thank you! (Sorry for my horrible English, I'm Dutch, and 14).