Misconceptions About Falling Objects
ฝัง
- เผยแพร่เมื่อ 12 ก.ค. 2024
- Yes, I have made a similar vid before. This is the Australian TV version for the ABC show Catalyst www.abc.net.au/catalyst/
Misconceptions About Temperature • Misconceptions About T...
The Mysterious Falling Slinky • How Does A Slinky Fall?
Why Are Astronauts Weightless? • Why Are Astronauts Wei...
And for those of you wanting a more General Relativity based explanation. Don't worry, it's coming.
Wow, how annoyed must that guy have been to come back and see a 12ft medicine ball on top of his car?
R/whoosh
@@claycartledge4935 r/wooooshwith4os
r/foundthemobileuser
r/ihavereddit
r/wooooshwithoutheh
r/im14andthisiswoooosh
@@anonymoususer638 r/overkill
@Liftsky thanks Mr. Obvious
I liked seeing how instead of making the people who didn't know feel bad, he was able to interest them.
You forgot to add "assuming no air resistance" to this!
It didn't matter in the experiment, due to the fact that the balls were basically the same surface area.
Though yes, in a perfect experiment, and theoretically, it requires a null air resistance value.
but friction is the same force applied to 2 object of different weight. So friction has more effect on the basket ball. It's just negligeable for both
Thanks!
I was completely over thinking this one because I thought them falling at the same rate was far too obvious. So I tried to reason that the air resistance would have less effect on the heavier ball as, despite the same surface area, it also had greater inertia.
@ Tom Badger You are TOTALLY RIGHT, drop these balls from 1000meters and the heavier one will hit the ground first, because it's terminal velocity is greater.
imagine dropping a basketball and an air filled ballon, they have the same size so they should fall at the same speed right? No because the baloon doesn't have enough force to "push" away the air
in a vacuum they would fall at the same speed of course
you could ask them "what will happen if you tie these two balls together",there might be two answers:
1. they'll go faster, because their weight adds up
2. they'll go by their average speed, because the lighter one is pulling upward while the heavier one wants to go faster
so there, you can easily explain and make people feel that there's somehow wrong with it
Are you saying that one of these two things will happen?
Willoughby Krenzteinburg
i'm saying that a thought experiment could easily show that "heavier falls faster" is wrong
Ok. Gotcha
That´s how Galilieo argued in his Discorsi. :)
@@alicehsuyaju The problem is that the havier indeed falls faster! A lot of people are saying, and correctly so, that mass plays a central role, because the air resistances acts in such a way that terminal velocity depends on mass. From same height, the lighter reaches terminal velocity first and therefore has less time in accelerated motion. Then it takes longer to fall.
Very interesting, I never thought of it this way but it makes a lot of sense. Objects with more mass take more force to accelerate up to X speed when pushed on wheels over a smooth floor... but the same acceleration delay applies to gravity accelerating the object in freefall. Crazy! Great explanation.
Excellent progression of understanding for the woman who first thought the medicine ball would hit the ground first, saw that she was incorrect and said she "needs to read more books", then proposed the idea of "maybe the weight is holding it back", then finishes by saying "like a heavy car that doesn't want to accelerate". I can only imagine that Newton himself went through this line of thinking. Nice job making this happen Derek, and the woman is impressive that she used prior knowledge to grow her understanding...out of everyone in this video, she's the most likely to remember this idea.
Hey man, I'm gonna ask something to you because your comment is the most recent. It's true that the 5kg ball is, in fact, falling slower to earth? But the difference is so small that we just ignore it?
I mean, let's suppose a ball the size and mass of the earth, and a ball that weight 1kg. The earth-sized ball would fall towards earth at 4,5 m/s and the earth would fall towards the ball at 4,5 m/s too, right?
Now let's go back to the 5kg and 1kg ball. Considering that the 1kg ball would fall at 10 m/s. It's correct to say that the 5kg ball would fall at 9,999999... m/s?
We can certainly ignore that difference. It's true that each ball and the earth approach each other at the same rate. I'd be interested to look longer at it and study how the acceleration of each ball in the system is affected knowing that we released each ball at the same time. In that case, the earth is only accelerating once, and not an infinitesimal amount "more" for the heavier ball. Either way, you showed how much it's absolutely fine to ignore it in the numbers you used. If the difference is .00000001 m/s/s, then that falls far within the margin for error that we're already allowing ourselves by calling the acceleration 10 m/s/s instead of 9.81 m/s/s. Certainly in my experience, it's most important to help people who are just learning this concept to understand the fact that all things acceleration toward the earth at the same rate (as Derek does here), rather than introduce the lesser affecting and more complicated aspects of the acceleration of the earth itself, or even air resistance. Air resistance can be introduced after this concept is mastered. The acceleration of the earth toward the ball can be considered as soon as they start working with falling objects that are hundreds of billions of pounds or more,, and will start to make the earth accelerate at a noticeable amount.
Except they really don't fall at the same time, because you know, air.
***** They're pretty much the exact same shape and size so, you know, they do.
Nope, they don't, because of conservation of momentum. Momentum depends on mass and velocity. The mass of the object does not change as it falls obviously, but velocity of the lighter ball increases ever so slightly slower (and tops out earlier, it has smaller terminal velocity, google it, the equation clearly shows it depends on mass) because the ball collides with air particles as it falls, and these collisions follow the conservation of momentum principle. Each such collision detracts from the momentum of the ball and given that it cannot detract from it's mass, it detracts from it's velocity. The less mass the ball has, the more it's velocity contributes to it's momentum, so the lighter it is the more momentum it loses. The only environment where they do fall at the same time is vacuum. Of course these effects are negligible at the distance he's using, but they are there and I would expect from him to do better and mention them.
Have you seen the experiment with a ping pong ball hovering atop a stream of air? That's basically falling in place, like skydiving in a wind tunnel. Now replace that ball with a lead ball of same size and shape. You think it'll still hover? Mass matters, if there's a fluid (water, air, whatever) in which the object is moving.
***** except the difference is, you know, milliseconds.
+Tim Stahel (Moustached Viking) That would depend on how long a distance they drop, and their mass - essentially, how close to their terminal velocities they get, and how big the difference between their terminal velocities is. You're correct that with a drop of about two metres, there wouldn't be much of a difference caused by the air, and it can be an useful demonstration about gravitational acceleration being constant. But trying to "remove" drag from the picture entirely just leads to further misconceptions because it's easy to see situations that obviously don't follow the false "rule" that things always drop with the same acceleration.
Consider a different experiment setup - what if you dropped a balloon filled with air, and a balloon filled with water? Both of them are the same shape and size, just like the balls in this video. Should they fall at the same rate of acceleration as well? Or is there something that the "simplified" model doesn't take into account?
Even when you add drag into the model, that's still not quite a full model about the situation. What about a balloon filled with helium, how fast would that drop in comparison to the air and water balloon of same size?
HerraTohtori I see your point, but I think the best way to look at this is to consider the experiment which was done on the moon in 1969. A hammer and a feather were dropped at the same time to demonstrate that the speed which an object falls at in a vacuum is unrelated to it's mass (although you can get nitpicky and point out that there is an atmosphere on the moon, however thin it may be). This is a major point which people don't know or understand about basic physics, though if it were not true, planes would not fly and parachutes would not work.
if u dropped the balls from high enough then the terminal velocity of the medicine ball would exceed that of the basketball and therefore would hit the ground first
ikr!
+Austin Moser thats right if you do it with air resistance,but without air everything falls with the same acceleration (9,81 cm/s^2)
Felixfex I guess that's true
+Felixfex Except if the ball wasn't dropped on earth, or when it has a mass large enough to influence gravity itself :P
Not so sure there... Obviously the drag from the air resistance would be relatively less on the heavy object (the drags the same, but the forces + inertia in play are much larger for the heavy object) - BUT, for this to hold true you have to know that they indeed hold equal aerodynamic properties. And the don't, since that comes down to surface material and "layout".. And perhaps the basketballs small "knobs" could give a similar effect to the dimples in a golfball.... (thus reducing drag substantially)..
I had no idea there were so many Aristotelians out there!
Galileo would be ashamed.
😂😂😂
2:00 I was afraid the ball was going to flatten Derek
The animation at the end where the ball squishes the car is completely unneccesary, I love it. Doing extra, even if you don't have to. You know who does that? Great people.
I love the old dude who assumed Derek was using magic!
i thought everyone knew this
+Elf Pyro As xkcd pointed out, if everyone knows it, 10,000 people have to learn it every day
true but it was a hyperbole
+Elf Pyro i thought so too... also when some says everyone they dont mean everyone.
So, what, when someone implies that a video was pointless because "everyone knew this", it's all okay because they didn't mean what they said?
In any case, it's a casual comment on TH-cam and we all know what was meant. I mean, heck, I've known about this since probably 4th or 5th grade and am surprised that they were able to find so many people who didn't understand it.
think of it more like a saying. its impossible to have Everybody something so we just say it as more than alot.
"Magic?"
We're making process as a species now.
"Process"
But what about a feather
@@paramsran1861 Air resistance
It is just amazing. Every single video you do is just awesome and so useful!!!! Great.
At this point, I'm just going to subscribe.
Don't know when I'll find the time to watch, but these are great!
Good job.
Depending on how high you drop it from the heavier ball would land first because of velocity. The lighter ball would be affected more by the air resistance.
nope Derek didnt mean this in his video.
thanks, thats relevant to know. because the air resistence is the same amount for both objects, as they are equally big/ same shape, but you are saying that the opposing vorce of the air resistance has to be calculated proportonally to the other two forces, gravity and inertia. now i get it
That is only true on vacuum. The air drag actually makes the basketball slower, and its terminal speed would be much lower than the black ball, so in a taller drop you could see a very important difference. I think you have actually caused more misconceptions with this particular video than the ones you ended.
Yes, but: The gravity force depends on the mass of the object, and the acceleration depends on both the mass and the force. The heavier ball gets more force, but also needs more force to move so it actually moves with the same acceleration. The air drag is, as you said about the same for both (perhaps a very small difference due to the shape and aerodynamics). Now, the heavier the object, the air drag remains constant, but the gravity force grows, so the less impact the air drag has on it. On vacuum, one balloon full of air and one full of lead will fall with the same acceleration. Not so if immerse on a fluid or gas, like our atmosophere.
Vladimir Pryshlyak Thanks man! Happy to be of use. Un saludo desde España
Actually the heavier Ball would Fall faster because the lighter Ball needs less air to fly (just like an airplane)
Vladimir Pryshlyak weight is how gravity affects the object F=mg weight is f g is gravity and m is the mass of the object
They are not talking about terminal velocity. Why do people who are educated beyond their intelligence make arguments about things that are not even in the presentation.
Very very nice way of demonstrating this while not going to the moon! Kudos for that.
Real good video! Compliments and thanks
looking at this 7 years later, you see how much has changed in production
This video is fantastic! If you don't mind me asking, what software did you use to do the 3D balls and the car being crushed? I've done similar visual effects with Element 3D in After Effects, but nothing that advanced. I'd love to know!
Another way of seeing this: _F=mg_
The acceleration _(g=9.81)_ is the same for every object on the earth surface, so they will fall exactly at the same speed (if they are the same volume or there's no air resistance).
Although the force of gravity does depend on the mass, as explained by Derek on the basketball there's a smaller force pushing on a smaller mass (same acceleration: _g=F/m=2F/2m_ and so on).
It's not even that the object is falling towards earth, it's that the earth accelerates towards the object as it moves through space. When we hold an object up with our hand, our body is connected to the earth so the object is also being pushed by the earth through our body, but the moment we let it go, the earth comes smashing into it, at 9.8m/s^2. So regardless of how massive an object is, the earth will accelerate towards it at the same rate.
@@BN99239 no... If your object has the mass of the earth, the earth will fall at 2*9.81 m/s^2 towards the object (in the reference frame of the object). In such a reference frame you actually "add up" the accelerations
I'm not sure about what you wrote but when you hold an object, your body is actually pushing it upwards. The earth doesnt pull it through our body but pulls it down despite our body. The earth also pulls you down, but the ground pulls you up. Etc.
My Physics teacher explained me this way:
According to Newton's second law, Resultant Force= Mass.Acceleration
So, if we disconsider air resistance, the only acting force to the body is weigh, wich is Mass.Gravity.
So, in short:
M.A=M.G
In this equation, as we have the same value of mass in both sides, we can disconsider it, so basically, A=G
Remember, this only disconsiderating air resistance and assuming that Weigh is the only acting force to the body in free fall.
Also, an experiment in the moon showed this. Astronalts dropped a hammer and a feather at the same time, and as there is no air resistance in the moon, both got to the ground at the same time.
Note: Sorry if I've ever used any wrong term, English isn't my first language, and I don't know the exactly translation of this terms to English.
@@joaotanaka3071 that's correct
How could these people possibly not know this???
Thank you Dr. Derek. I have watched your videos for the past 4 years. I was always stumped as to why they would land at the same time, when one object has a greater force of gravity. That being said I knew how they would behave, but not why.
Now I know why, even in areas with air resistance they land at the same time.... Inertia is a property of matter
They would not necessarily land at the same time in areas with air resistance.
The balls landed at the same time despite air resistance because they didn't reach a high enough speed for the air resistance to become a significant factor. If dropped from a larger height, the medicine ball would land first.
I am currently taking my first classical physics course on mechanics in college and I never really tried to understand the concept of inertia. I learned something by watching this :) I thought I knew the basic idea of this stuff already but I had ust lied to myself.
I have some sympathy with people who get this wrong by arguing that gravity pulls more on the heavy ball, because it really does. The problem is that people don't really have a good intuition for inertia. We have all tried lifting heavy objects, but the thing that limits us tends to be the force due to gravity rather than the inertia. The best way to get a feel for inertia is by sliding objects of large mass on low friction surfaces, but that is a somewhat contrived situation compared to lifting the shopping out the back of the car.
Rolling heavy objects works as well, like pushing your empty cart vs your full cart when shopping. The heavy cart is both harder to get going and harder to stop.
Ekitchi Hoshi Exactly. But for some reason people just think of the weight of an object and forget about inertia.
I've noticed that skating with a really heavy backpack makes it go a bit faster in the downhills.
It's crazy. And also the falls are faster and harder.
Nicko G. Yes you go faster downhills on a skateboard with a heavier weight, but that is because of friction.
Without friction, you would go just as fast no matter the weight.
With larger masses, you get a greater weight and a greater inertia but the same friction. Friction counters a smaller percentage of the weight for heavy objects than light objects.
For the same reason the feather and roc fall at different speed when there is the friction due to air, and at the same speed in a vacuum.
Skating downhill is a completely different situation. You're not in freefall, so what's actually happening is the force due to gravity is being converted to rotational velocity for the wheels. It's a more complicated equation where the mass doesn't cancel out.
This helped me understand the first concept in physics. Can you do more interesting experiments for normal college physics concepts?
Every nerd who knew the answer was waiting for that glorious nerd show up and present our holy kind at its best. Thank you mate...
What if both objects reach terminal velocity. The heavier one should be falling faster at that point right?
No, regardless of terminal Velocity, both objects will hit the ground at the same time
+PolyvinyLs Not true. Terminal velocity is a function of mass, shape, area, and density of surrounding air.
It is only when air drag is negligible, that both objects hit the ground at the same time.
+Fischer Hill If you measure accurately enough you would probably see the difference before they do that.
Yes. The medicine ball actually does fall that little bit faster because it's heavier, but that's not because of gravity. It's because the air slows the basketball down more than it slows the medicine ball down. If there was no air, they really would fall at exactly the same speed.
If they reach terminal velocity the heavier one will fall down first because it reached terminal velocity a bit later than the lighter one. Galileo stated this on his reflection of the leaning tower of pisa expirinent
The acceleration due to gravity near the surface of earth has a value of 10 m/s² (approximately). It is same for all the objects, falling under the action of gravity.
Not quite, to my understand gravitational field strength (g measured in N kg^-1 which is actually the same as m s^-2) is the same for all objects however the acceleration is not. F=ma only applies to the resultant force and because of air resistance (which this video doesn't consider) the resultant force =/= weight. If there was no atmosphere then F=ma=mg => a=g however it's more complex than that and to really really over simplify it F=ma=(mg-A) => a=g-A/m where A is the force due to air resistance.
Sorry about how this is an old comment and stuff and my answer is probably very wordy.
My teacher gave us this vid to watch and I’ll never see her as boring again cuz this is my fav channel
I've heard the fact that they fall at the same rate explained a hundred times and its basic knowledge at this point. But this is the FIRST TIME someone has actually explained why by including inertia which causes the idea to make perfect sense that even a kid could understand. This is what aggravates me about most education methods. Simple explanations like this cause the idea to make sense and be remembered by far more people than one that feels more like "I know it doesnt make much sense, but just trust me, its true" which is what you get most of the time.
Do most people just not take physics classes ever? I feel like asking which would hit the ground first is like asking what 1 times 0 is...
pcakes I guess it's 1
pcakes no , unfortunately with the current education system we’re taught only to remember certain things and use fancy key words as a test of intelligence in a test. We don’t get full understanding on how and why things happen most of the time. E.g all objects will fall at the same time due to inertia ignoring air resistance. So when a feather and bowling ball are dropped, the feather will land past due to air resistance which comes from the surface area, so if you took a sheet of paper and a notebook- both size A4- why does the sheet fall second, considering they have the same surface area. I’m not trying to single you out but prove to you that we don’t have full understanding on how things actually work
I'm only in 7th grade so I'm not taking physics classes yet ._.
@@dogeyexists ok doge that's fair im sorry
Van What country are you from ?
I was shocked how many people you asked didnt know two objects of different mass hit at the same time. At least here in Canada thats like the first experiment they teach you in science class.
I was surprised about that as well (I'm from Europe).
china+1
I need to go and read more books. Excellent response, and an excellent explanation. Nice!
I knew the answer but I was glad to hear the theory behind it! Sometimes you know how stuff is, but not really why!
Imagine a bag of sand falling- a collection of grains. All together, they fall at the same speed. Each light grain falls at the same rate as the whole big bag full. The bag could be as heavy as an anvil, but each light grain falls as fast as an anvil.
This example does not speak to me. They fall together because they are connected. If u delete the bag they could fall at different rate because of different air resistances.
This is almost always true, unless you are dropping from a much higher height (lets say enough to have terminal velocity). The basketball will reach terminal velocity, much sooner than the medicine ball, so the medicine ball will hit first in that case.
I love that you used vallenato during the drop sequences :D
I heard that and I thought "nahh can't be vallenato" but I'm glad someone else noticed!
I appreciate the advice! I've been trying to force myself to appreciate the beauty of mathematics - and it's exactly things like that that I am trying.
Recently learned that the mass/weight at the end of a pendulum doesn't effect the speed of it's period of oscillation 0.o . Cheers!
You are ahead of Socrates
How do people not know this? Or do you edit out all the other 1000 people who knew this?
I'm sure he cut out all of the people who knew the answer.
Some Guy
I get the same feeling for every video.
No, people are just stupid.
I think he goes to an area where he knows people are dumb.
THE ZOMBIE TRAINER
Hahaha
I'm seriously wondering how these people got through highschool...
Depends on how good your professor is at making the subject interesting, I hate physics due to some really old school teachers , although I’m starting to find it kinda interesting since I started looking into it on my own for some exams
@@andreaberetta9656 Whether you like it or not, you'd still have to pass the class
@@MaxArceus what i'm saying is that you'll study for the class and forget everything as soon as it's over
@@andreaberetta9656 Sorry, but that's kinda stupid. Even if it doesn't interest you much, there's a reason you're being taught those things. Why'd you just go forget it?
And sure, you can forget some things, human minds are not infallible, but something as basic, and important as this? Given you're subject to the laws of gravity literally 24/7.
It's not like he's asking for the formula to calculate how long the fall will take.
@@MaxArceus because that's how people are. Do you honestly think you'll remember every thing If you don't ever use that info for years. I can't properly remember things I've studied this year. And I really do try to learn them.
And saying how you can forget details about something you constantly are aware of.
What does your nose smell like? Do you think it dosen't have a smell? No it does but your brain just *forgets* it's good at ignoring repetitive information.
It took so much time for humanity to even question why things always go down. We forget things because they are always there.
Idk why the awesome editing done in this video is no longer used :( So good
Read the description - this segment was for a TV programme in Australia. They probably handled the editing themselves.
I've seen this video when I was in school and I loved it, but now that I'm re-visiting it, I must point out things like air resistance and terminal velocity
This video is not about air resistance or terminal velocity. In fact, air resistance is a fundamental reason why so many people have misconceptions about gravity - which *_is_* the point of the video. You can open any entry-level physics textbook and you will find that drag is ignored when talking about the fundamentals of gravity for the precise reason that it is the primary source of confusion regarding gravity.
didn't we all learn in grade school that Galileo already proved this?
no
Galileo didn't prove this, he observed this and postulated this. If anyone could be said to have proved it, it would be Albert.
@@PackerBronco No, its Newton. F= m a and F= G M m /r^2 so the small 'm's cancel out on equating the two forces and give us a constant value for acceleration a = G M / r^2 which is nearly equal to 9.8 m per second squared.
@@devnampriyapriyadarshi1331 Yes but that assumes that the "m" in Newton's 2nd Law is equal to the "m" in Newton's Law of Gravity. In other words that inertial mass is the same as gravitational mass. Newton assumed it to be true and used that assumption to derive the fundamentals of orbital mechanics. Einstein took that assumption one step further with General Relativity's restatement of the Equivalence Principle.
@@PackerBronco really just semantics. You don't "prove" anything in science you just observe it and follow the scientific method. We are victims to the unreasonable effectiveness of mathematics.
Of course acceleration is the same for everything on earth, but only in vacuum. With resistance from air, I guess the light ball is slowed down at a higher rate than the heavy ball, therefore the heavy ball should hit the ground slighly earlier. Am I right?
yeah termvel is slightly higher for denser object with similar aerodynamic features
The heavier object also pulls the earth or moon to it faster so technically heavier objects do fall faster, even in a vacuum.
The thing that never gets talked about with these examples is that acceleration is the same for all objects in a gravitational field, but terminal velocity does depend on mass
Mass alone doesn't determine an object's terminal velocity. It's the air resistance per unit of mass that matters, and that can be quite different for objects with the same mass if they have very different densities or shapes.
It's fun and instructive to compute the velocity of an object when it hits the ground (discounting air, of course) by equating gravitational potential energy to kinetic energy as in mgh = 1/2 mv^2. Immediately the two "m" terms cancel and what's left has no dependence on mass.
Actually, the heavy ball will fall faster because it has the same area and the same air resistance as the basketball. This effect just doesn't show up for such a small height.
lol, lots of physicist testes it by going it to a rollercoster and still they fall at the same speed. don't follow your own desire.
lol, lots of physicist tested it by going it to a rollercoster and still they fall at the same speed. don't follow your own desire.
It'll still fall a little bit faster, unless you do it in a vacuum.
the problem here is, that since neither ball was pushed, they were just dropped, none of them had initial speed, and their terminal speed will be v = g*t where t is time of the fall before hitting the ground, and g is the acceleration due to the gravity, which is a constant, which means it's always the same, no matter what, as long as you are on earth.
Therefore, speed of two objects falling from same height is in no way influenced by either their shape, size, weight nor color.
It is what it is.
A vacuum shouldn't matter if the objects are the same size and shape. They fall at the same speed because inertia scales with mass at the same rate that gravitational force does.
Divide gravitational force by mass and you get gravitational acceleration.
Or F/m=a
...
(Fullmetal Alchemist?)
Liked your comment just because of the fma part
Don't forget that this equation only work if the mass m is constant ...
(It's the principle of equivalence in Fullmetal Alchemist !!!)
That's actually a good way to remember it :)
I am so glad I wached this!
thats like saying a feather and a nickel would hit the ground at the same time. they wont. you need a vacuum
That's the entire point. This video is about GRAVITY - - not drag, so drag is being ignored, and in that case, a feather and a nickel will indeed hit the ground at the same time - something you acknowledge to be the case.
i think if the height is large enough, the slight difference btw the net force will show.
Weight of the larger mass is larger.
Net force = weight - drag (air resistance)
since there is difference in weight and we assume both have same drag due to same shape and size (discounting other factors), there will be slight difference in net force, which will be apparent when both objects are dropped from high enough.
Willoughby Krenzteinburg I have a question that has been bugging me for a while. What if the moon fell to earth, Idk the gravitational acceleration of the moon but lets assume that it is 3m/s2. How fast is it's acceleration towards earth? will it be 13m/s2 or what.
Avo Christos the accelerarion of the moon toward the Earth would be the same as any other object from the same height. The Earth would also noticeably accelerate toward the moon, but those accelerations are independent of one another. You don't add them together.
Based Vsauce well the feather is kinda pulled everywhere by wind
"I am surrounded by bakas!"
Two words...
Air. Resistance.
The balls are almost the same shape ( and size) so that doesn't have much of an impact in this experiment. It would however change the result if the balls were allowed to reach higher speeds (terminal velocity of the basketball is lower because of your favorite Air resistance).
I have a question that i really need an answer to. So we know that a heavier object actually falls slower because of initial but does an object falls slower if it has high momentum acting horizontally? we know two of the same item will fall to the ground at the same time even if the other 1 is projected horizontally, but does the same items, one with a higher momentum make it resist change more? if you need me to rephrase please let me know. thanks in advance
A 3 minute video explains it better than books worth of hours of knowledge.
You just love your inertia, don't you.
Nathan Wood You spin me right round, baby, right round. In a manner depriving me of an inertial reference frame, baby, right round.
this is a 8th grade physics subject in turkey
+Özcan Yılmaz Pretty sure it is everywhere. I don't get how they couldn't have known this.
yeah dude everytime i see videos like this i think of that
+Özcan Yılmaz Me too. Some of the subjects are very trival, however I still love his videos and the majority is still mind-blowing and much more complicated.
+Victor Brink Wos they ask many people and only 1% of them don't know it, so they show only those who don't know it.
+Özcan Yılmaz Its actually one of the first things you learn in physics class
Wow! Vallenato rhythm in this amazing channel! 🥳
The similar video he is referring to in the description is his second ever TH-cam video. This video can be found on his first TH-cam channel, "Derek Muller", which is also his name. Came across this gem when looking for a veritasium video. Also, this is the exact same place where he filmed the original falling object video.
"I need to read more books." BINGO!
Ding - ding - ding - ding - ding
who would ever imagine that people out there still not knowing this....
RavnoUK I think they are acting to show themself stupid because it make more our mind work with some ideas which make easy to understand and more memorable.
weight does effect speed terminal velocity occurs when the air resistance "drag" force equals the weight of the falling object but heaver objects take longer to gain momentum relative to max " terminal velocity" so if they tried dropping off something higher u could get different results
the key is that we think more force is means faster but this is for objects that have same mass, when masses different then more force doesn't mean the object will always move faster you have to take the mass to account. So more force tends the objects move faster but at the same time more mass makes movement harder.
The heavier ball will always hit the ground first, but it may not be perceivable or measurable. When it comes to situations where the gravitational force of one object is exponentially larger than another, (planet vs basketball) the mass of the smaller object is usually not considered in the measurement of gravitational force. This is why we tend to say that gravity is a constant 9.81 m/s^2 for all objects near earth. However, in reality the gravitational force of any object will also act on the earth causing a slightly higher gravitational acceleration.
+something1random23 but if the experiment is to drop both objects at the same time then the acceleration of the earth towards the objects will be the same for both ;)
firsy However, you can't drop the objects and have them occupy the same space. This means the acceleration of the earth will be angled more toward the heavier ball.
something1random23 A bear shitting in Wyoming will have just as much (and just as insignificant) of an effect.
Willoughby Krenzteinburg I never said the difference was significant. I said the opposite in fact. This is all a hypothetical situation where nothing else is having a gravitational effect on earth as well as no air resistance, though air resistance could make the results considerably different depending on altitude.
something1random23
I see. A better mind experiment then would be dropping two balls from the same distance from the Earth's center, but on opposite sides of the Earth. Then the Earth would have a net acceleration toward the more massive ball.
It is still important to point out that the acceleration of the balls themselves has not changed. In your original comment, you implied that you attributed the Earth's independent acceleration to the balls' when you say the gravitational acceleration would be greater on more massive balls and not necessarily a constant 9.81 m/s².
Two ways this is misleading.
1) 9.81 m/s² is in no way a constant. It is variable. This just happens to be the gravitational acceleration for objects at sea level on Earth. If you are below or above sea level, it is slightly lower or higher. It is about 9 m/s² for astronauts in orbit. There is a constant G-force (a unit of acceleration) which is based on the acceleration due to gravity at sea level, but the gravitational acceleration itself is not a constant.
2) two object that are the exact same distance from the Earth will have the same acceleration due to gravity - no matter their difference in mass. Any acceleration of the Earth is independent of that.
You lie! Acceleration is not the same for both objects.
F1=M1*g-F_air_resistance
F2=M2*g-F_air_resistance
a1=(M1*g-F_air_resistance)/M1
a2=(M2*g-F_air_resistance)/M2
a1-a2=(g-F_air_resistance/M1) - (g-F_air_resistance/M2) = F_air_resistance/M2 - F_air_resistance/M1
If M2>M1 => M2 hits the ground first
THAT... but resistance is futile...
well at least at this scale, and measuring with a human eye..
Touché. I'm surprised that there are people who didn't know this.
finaly I got the explanation I was looking for... objects "fall" at the same rate or with the same acceleration torwards earth, because of the ratio between gravity and inertia...
now gravity makes a little more sense than before jejeje... thanx!
cheers
Someone give this guy a TV show
they only land at the same time in a vacuum
otherwise it depends on the drag coefficient
if the drag coefficient is the same the heavier object will hit the ground first
Correct me if I'm wrong, Theoretically the black ball is supposed to fall "A Very Slightly" faster than basketball because it has more air resistance due to its mass. I'm saying this on the reference of of Galileo's experiment of falling bodies.
Technically the medicine ball IS accelerated toward the Earth more quickly, but the difference is infinitesimally small. Think about two basketballs in deep space, they are attracted to one another albeit at a minuscule acceleration. Now replace one basketball with a planet, and the acceleration increases to macroscopic levels. It's the total difference in mass that makes a difference, and because the difference in mass between basketball + Earth and medicine ball + Earth is so small relative to Earths mass it makes no difference realistically.
The force depends on the product of the masses, not the sum. If the medicine ball is 10 times as massive, the gravitational force will be 10 times greater.
The acceleration a = F/m will be the same for both because the mass cancels out.
You can hear his Aussie accent kind of come out at times
This is so wrong on a fundamental level! It's true what they say for free falling in VACUUM. The only reason the heavier ball doesn't fall faster here is because of the small height from which both balls are dropped. If it were much higher, the basketball would reach terminal velocity sooner and the heavier ball would keep accelerating and fall faster.
Actually, it's RIGHT on a fundamental level. That _fundamental_ being how gravity affects falling objects - which is what this video is about. This video is not about how drag affects falling bodies. Drag is being ignored because they are talking about fundamental gravitation. In real world applications (orbital mechanics, etc.), there is no drag to worry about anyway - and since Veritasium does not have access to a vacuum chamber, an imagination will have to do. You have one of those, right?
Willoughby Krenzteinburg
By trying to clear a misconception, you are creating an even bigger one so it's not OK. There are actually many people who do not understand that IN AIR HEAVIER THINGS FALL FASTER, and it seems to me that it's possible that this kind of teaching physics lead them to that.
Leeroy Kincaid Actually, the opposite is more often the case. People have misconceptions about gravity because of drag. It's a process. You cannot possibly understand how drag affects a falling object without first being taught how gravity ALONE affects it. In fact, if I asked you to tell me EXACTLY how a falling object behaves in an atmosphere, I challenge you to explain that to me without first analyzing how gravity alone would affect it (HINT : you can't do it). Again, it's a process, and learning fundamental gravitation is step one. This video addresses step one. There are many other sources that get into more details. This is not one of them.
Sample question for you :
Suppose I drop a 1 kg object from 10 meters above the surface of the Earth, and it takes that object exactly 1.75 seconds to reach the ground. What was the average force of drag acting on that object?
Answer this question, and explain the answer to me WITHOUT addressing how gravity alone would have affected that falling object.
Go.
Willoughby Krenzteinburg
Of course you need to know basics first, but watch the video again - the guy acts smart and asks people which ball will fall first. He DOES NOT point out - in VACUUM!!! Therefore his answer that they fall at the same time IS WRONG, ecpecially since he afterwards lets them fall and claims they fall at the same time (which they do not, but because of the small height and imprecise measuring it seems they do). This video is absolutely catastrophic from an educational point of view and makes more mess and misconceptions than the one it was originally meant to clear... I'm sorry because you're trying and clearly have good intentions, but this is not good teaching.
Leeroy Kincaid
You are really over analyzing the situation. This is how gravity is taught all the time. Perhaps you missed that day or something. As far as I am aware, they do not have vacuum chambers in classrooms across the world in which to do these demonstrations, so - like I said - some imagination is required. In this particular demonstration, it is not necessary to point out that we are ignoring drag because it is negligible. In fact, as you correctly point out, the fact that they might not have been dropped at the same exact time has just as much an impact on the outcome, but obviously it is ASSUMED that they are. It is also assumed that the ground where they land is reasonably level and even - and again - this probably isn't the case in reality. In fact, if you were a real uselessly anal person (it seems you are in fact this), you would point out the fact that the Earth itself is attracted more toward the more massive ball, therefore accelerates more toward it. However, the vast majority of logically thinking and reasonable people will assume that all of these negligible peripherals are being ignored. Again - apparently, you are not a logically thinking and reasonable person because you keep mentioning drag.
I will quote only your very first sentence :
"Of course you need to know basics first"
This is correct. That's what this video is doing. If you can't get over the fact that it doesn't mention drag or account for it, then my response to that would simply be :
YOU ARE NOT THE TARGET AUDIENCE OF THIS VIDEO.
And all this being said, lastly but certainly not least of all : It is a TH-cam video; you are not owed anything. If you can watch this video and claim that it is "catastrophic" educationally, then you have not watched very many TH-cam videos.
I'm done. Have a good one.
I think you should also add in terminal velocity this element will strongly effect the time take for ball to reach surface of the earth if distance is lot bigger, where the heavier ball will take shorter time to reach earth surface
I already knew that objects fall at the same rate if air resistance isn't a factor but this is a really interesting explanation, I thought I understood why it happened but I didn't
missing these videos about physics...
I was actually mad at my physics teacher today when he asked us a smilar question and when I said the balls hit the ground at the same time due to inertia and he said i was wrong...
What was his reply though?
This needs to be expanded on in terms of terminal velocity. The medicine ball and basketball only fall at the same rate over a short distance, eventually the medicine ball will reach a higher terminal velocity because it has more inertia capable of countering roughly the same amount of drag as a basketball. As speed picks up, acceleration decreases for both balls but the medicine ball will reduce in acceleration at a slower rate.
+Sigma Octantis
That's about air resistance. The air accelerates the heaver ball less upwards than the lighter one.
I think air resistance and friction are a few of the main obstacles in understanding mechanics, so it's fair to discuss the whole thing without them at first.
+Taxtro but he should have at least told people to ignore that, otherwise people will think they get it and then later realize that a balloon doesn't do what they thought this guy said it should and they stop believing it.
I would like to venture an alternate explanation. A greater gravitational force on the black ball is the result of its greater mass, which results in it having a greater momentum, w.r.t. the orange ball, due to its mass. The rate of change of velocity, i.e., acceleration, of the balls doesn't depend on their masses, but on the mass of the object pulling them (the earth) and the distance from that object's centre (which, in this case, will be the earth's radius added to the equal height of both balls above the ground). As these quantities do not change, the balls have an equal acceleration, called the acceleration due to gravity.
Great video, anyway! Thank you!
Adding the extra height above the ground to the earth radius doesnt make much sense. Earth isn't spherical
It's amaizing how many people skipped physics lessons in school.
But he says nothing about air resistance which is a big key in what he's talking about
I hope one day Derek asks me physics trick-questions on the street. I will be _so_ ready.
Yes the acceleration due to gravity is equal, but air resistance is also equal and affects the medicine ball less. Therefore, the medicine ball does fall slightly faster. That difference would be more exaggerated if the drop height were higher.
Yes exactly, thank you for acknowledging the existence of air resistance.
"Everythinf accelerates at same rate and falls at same time" That is if none of those objects reach terminal velocity. Heavy object's terminal velocity is higher, therefore if we'd drop balls from 1 km up, heavy one would fall faster due to weight of ball. Light basketball would be more affected by drag, and therefore stay above heavy ball during the fall.
drag is being ignored here
i know. That's because of small speeds.
Kacper Szczerbiak Not necessarily the small speeds. You could consider drag and then deem it negligible for real calculations due to the small speed. Drag is being entirely ignored because it is the reason that there are misconceptions about gravity in the first place. Drag is always ignored when talking about how gravity and gravity alone affects falling bodies.
i see what you mean, and yet the phisics won't ignore drag. and it's not like those balls were dropped in vaccum. drag was obviously here, but due to small speeds it was just irrelevant. however i get that you're trying to say that drag wasnt even counted in.
Kacper Szczerbiak
Physics DOES ignore drag when it is teaching fundamental gravity. Otherwise, it can't teach it.
Dude, if you do this kind of science divulgation videos you shouldnt divulge false information. The terminal speed of heavier objects is higher than from lighter objects. So both object will fall at the same time if the lighter hasnt reached terminal velocity. So heavier objects fall faster if you give them enough space.
Terminal velocity only hits in sufficient distances and is different depending on atmosphere. For all intents and purposes, what he said IS correct as far as the average person is concerned. Sure you could go on about terminal velocities, distances traveled, what kind of drag is in place, curvature the space it's traveling through, shape of the objects and the resistance the shape gives, etc etc, then it might as well be a video long enough to explain the entirety of a physics course. This isn't necessary.
I mean, if you want to get technical, if you were falling with the two spheres, and there was no other reference point to go by, there would be no way to tell if you or the spheres were moving at all. None of this is necessary for this video explaining a simple principle that holds true for every day life.
In vaccum there is no terminal velocity for falling objects... for educational purpose he left aside air/fluid dynamics
*****
Most people call it a vacuum.
Raimar Lunardi So practicall... we live in vacuum...
Terminal velocity is when the pull of gravity and the air resistance are equal. The heavier ball will always hit the ground slightly faster in air due to the simple fact that the amount of air resistance affecting the balls is equal, but has a lesser effect on the heavier ball because of the higher inertia.
Wow,really great video!!!
I miss this kind of videos.
every child in china know this
knows* ...
*period
Every child in most places know this
"every child in china know this"
They better! I don't want my nikes glued together by some ignoramuses!
+crikey mate oh man someone direct Mr. Yang to the nearest burn ward
again, common knowledge is not so common
I fully realize, I was just surprised no one mentioned it in the video. It doesn't even have to be a different shape. Imagine you drop a beachball and a medicine ball that are the same shape, the beachball would then obviously fall slower.
Interesting, I haven't thought about this nor did anyone tell me before despite it happening everyday. Maybe because the falling objects we usually see have different size and shape. So the acceleration is around the same until they reach their max speed.
Im 13 and i know the answer
This comment is useless.
Some Guy k
Im 13 too, but I knew the answer when I was 11
and you think you're special
Kormarg no ;3;
Fun animations Derek!
There'll be a lot of maths to plough through that look legitimately scary the first time you lay eyes on it, but if you hang on, it'll be worth it :)
Good luck!
This is correct as long as they are of the same shape due to air resistance having different effects if they were different shapes
If given the choice to drop one or the other on their foot from 6 ft in the air, the obvious choice is the basketball
but that is because we perceive the force (f=MxA) where the weight of the black ball is more and will exert more force.
But the gravitational pull is still the same
It's slightly disturbing that they were able to find that many people, so easily, who are unfamiliar with this fact. Whether you arrive at it through an understanding of Newtonian Laws, Relativity, the results of Galileo's classic experiment (which they;re recreating word for word), or even just personal experience playing ball as kids...people SHOULD know this.
Technically, the medicine ball will fall faster, but in this scenario the acceleration difference is neglible. While gravity is applying the same acceleration to both objects, the medicine ball will have a higher force, and because both objects are aerodynamically the same they will get the same friction from the air, and the friction will have a bigger effect on the basketball.
+Federico Gonzalez Would not the more massive object have more resistance to the change in inertia, thus canceling out or equalizing the effects of the added force over the less massive object?
xferociousx yes it will have more resistance due to inertia, that's why it requires more force. But the air resistance will be equal in both objects, and because the heavier object has more force, the change in net force due to friction will be relatively less making it accelerate (very slightly) faster.
Could you do a video to do with objects (balls) of different shape and size and how they fall in comparison to one another? Do objects of the same size and shape but different masses have different terminal velocities or the same terminal velocity?