those older videos of yours are very cool, simple but informative. I've never seen them before, must be that new youtube algorithm coz they pop up in my recommendations
i remember these were the only kind of videos he made. Great work, simple and very informative. He's turned to more long winded philosophy it seems lately.
you know this guy's philosophy actually works. Even i thought that gravity is the only force acting in the beginning in the beginning. But then when he started asking if there are any other forces i started remebering physics lessons in my school. kudos to your philosophy, Derek!
Omg "it's just a theory..." "Nobody knows what it's really about" "it's thing indescribable thing that keeps us from flying off into space" Please kick this person from whatever college she's on..
Asking a philosophy/postmodernist/cultural theory student, questions on science is gonna elicit such a retarded response. Better not ask someone who's not been tainted with such thinking in the first place.
Thank you for making this video. As a high school Physics teacher, I can tell you this works great to get students thinking... and to start a lot of discussion around free body diagrams and analysis of systems. Wonderful job!
I've been using this as an intro when I teach forces to my 8th graders for 5 years now :) glad to find your channel and see that you are still making new content! That's awesome ^_^ keep it up man.
Gravity (not really a force but it acts as one), normal force, friction, buoyant force, probably some tension, centripetal force...idk what else maybe I got em all.
Or simply said, Understanding would be finding an association between Theory and Practice or between different concepts. More simpler, Understanding is connecting the dots.
nah, many scientest know their stuff, but also will sound utter idiots in art, philsophy, or where they come from or their purpose of living... people should be modest. but they can not. that is the real force..
@Tossphate Yeah, I'm getting around to the 4 force video (or 3 or 5 depending on how you want to look at it). I know it's been awhile but I've got distracted with other things. Why can't you walk through walls is one I'd like to do...
when standing up. we have :- - gravitational pull which pull us down to the center of the earth. - atmospheric pressure. a push (1atm) - and a normal reaction force which is a push on an opposite direction of gravitational pull. - this force is important because it will make the resultant force , F = 0. so we can stand still. -and maybe some friction which is a pull. if i was shaking or fidgeting or moving
@MrTriple3D no that's wrong there is gravity acting on that falling body with respect to a person standing down on the ground without moving. What you said is correct with respect to the body falling down or a body falling down freely along the the initial body .
Do people not take basic physics anymore? Unbalanced forces cause acceleration, therefore another force must be canceling the gravitational one. This is called the normal force.
Scooby Jim Doo not if they are not trained. Normal force, though, is the Earth's hold on you. It's just called that way cuz how its oriented normal toward the "flat" ground in which we stand
I'm a little late but I want to say, that we are accelerating a little bit due to the rotation of earth. Changing direction of movement means accelerating, right? Or am I wrong?
@@jonathanlange1339 if you want to get super technical and big picture. yes change of direction is acceleration. the earth (and therefore you) is constantly accelerating toward the center of the sun. this acceleration causes us to go in a circle (orbit) around the sun. without that acceleration earth would fly in a straight line away from the sun and we would freeze to death without the heat of the sun.
My answer would be there's the force of gravity and the equal normal force from the Earth. But that's only in Newtonian physics. A more accurate answer is the Einsteinian one, which is that gravity is a curvature of spacetime, not a force, so the only force acting on you is the normal force, which means you're accelerating away from the center of the Earth.
Actually, even if you are standing still, the friction still has an effect. Try to stand still on the ice and see how that goes :) It's called static friction.
Gravitational force, The normal reaction of my weight The centrifugal force Force due to air pressure And force from inside my body to ballance the air pressure
I don't think the Earth is pushing you up. It's pulling you down, the upward force is you pulling the Earth up, and your body resisting the downward force with muscles and bones.
4 words.. a push or pull forces that acting on you atm: -force of gravity (force on person exerted by earth) -newtons third law tells us that you, the person, exerts a force on the earth that's equal and opposite -theres a normal force exerted by the earth thats equal to the force of gravity b/c of newtons 2nd law stating that no a=equal forces -windy day means air resistance, so the force of air -again, the force on person exerted by the air means there's an equal and opposite force on air thats exerted by the person. -static friction force also prevents you from moving, so newtons second law tells us that the force of static friction is equal to any other horizontal forces.
Ok first you don't have to include the forces *by* the person. And secondly I'd like to add on first point. Gravity also acts between us and every other thing around. The air, humans, animals, walls, etc all exert gravitational force on us
Force is rate of change of momentum with respect to time: F= d(mv)/dt Thus via the product rule: F = v(dm/dt) + m(dv/dt) typically we can regard the mass of an object as constant (ignoring things such as relativity and rocketry) so dm/dt = 0 so: F = 0 + m(dv/dt) dv/dt is the rate of change of velocity with time, i.e. acceleration dv/dt = a Therefore: F = ma Congratulations, you just derived newtons second law of motion. :)
If iam standing (without any motion) 1.gravitational force: which pulls me down 2.Normal force which opposes the body from gravitation While motion (first 2 forces are necessary which I mentioned above and other two forces also necessary to move) 1.To move forward I need frictional force ,with out frictional force you are slipping (no grip) 2. Muscular force inside you
I had thought that initially as well, but he mentioned that he was asking philosophy students (1:17). With that and the demographics of the interviewees in the video, I imagine he's on either a university campus or academic institution of some kind. There's (or was) a fair chance he'd run into someone who would be able to answer.
This is not a video about what forces are. It's a video about which two forces the presenter knows. What about the fundamental interactions (graviational, weak, strong, electromagnetic) that keep our atoms, protons, quarks together and prohibit them from disintegrating into who knows what? WHAT are those forces? Where do they originate, how do they work, how do they differ from matter? That is the question behind "WHAT IS A FORCE?"
0:52 FTW 1:08 Said the almso exact same thing in another video: "It's an indescribable thing that keeps us from flying off into space " 0:52 > 1:08 | 3:04 LMFAO I love how he shakes his head like he's laughing at them.
they have a left lobe (or vise versa) dominant that is responsible for "soft skills" like language, social skills, communication skills etc. The other lobe is responsible for logic, abstract thinking, spatial vision etc - all needed for engineering or science.
Gravitational Force, Force from the ground pushing up, and to be more complete these two don't exactly cancel (by about 3 newtons or so) because I am accelerating in a circle once per day. There is also air pressure squeezing me and my body pushing back.
Question!: Do you ever interview someone who knows the topic like a text book? i.e.: Did anyone tell you right off hand that Force was mass multiplied by acceleration?
There are also negative accelerations. They are a necessary and absolutely valid concept. Some might call it deceleration, but in physics, it is all acceleration. Most of the time, acceleration in the direction of motion is positive, and acceleration in the opposite direction of motion (deceleration) is negative. It doesn't have to be that way. Like I said, as long as you are consistent, it doesn't matter. The results will be the same.
well the gravitational force doesn't pull me down to the earth, it pulls me and the earth toward each other. That keeps the centrifugal force of the Earth's rotation from slinging me out into space. Inside my body, there are the atomic forces at work, the strong force keeps the nuclei of my atoms together. The electromagnetic force is responsible for keeping me together at the molecular level, as well as keeping me from passing through other objects. The atomic weak force is responsible for radioactivity, it is believed that it is also (at least in part) responsible for the transmission of smell. Atmospheric pressure is largely another expression of the gravitational force. All that, and that isn't counting the elector-chemical interactions in my brain and nervous system to tell my thumb to overcome inertia and fiction by unleashing potential energy stored in my muscles into kinetic energy to Swype patterns across my pocket computer's touch interface keyboard to compose and transmit this information.
+Franklin Allen Remember that the "centrifugal force" is a fictitious force and doesn't actually exist, its just an apparent force in a rotating reference frame. It would just be your inertia causing you to fly out to space if the force of gravity was suddenly removed. The only force involved in circular motion is the centripetal force, which points towards the centre of rotation. And gravity is what supplies that centripetal force, keeping you on the earth, and satellites orbiting.
+Alex Dlugosch you are technically correct, which is the best kind of correct. However, wouldn't the centripedal force also be just an apparent force and not an actual force since it is just an expression of gravity? +Florin Toader I cannot find a link, it was a tidbit from an old episode of a science program on scent, I wasn't to say it was Nova, but it was a long time ago, also the narrator said it was theorized that radioactivity was responsible for certain aspects of certain scents, like part of the aroma of a banana was caused by the radioactive decay of the potassium in the banana. That without that reaction, a banana would smell much different, if at all.
+Franklin no centripetal force is not an expression of just gravity. If you have say a rope and a mass tied on it and you're swinging it in circles. Then the rope is transferring the centripetal force (through tension force) and pulling the mass to center, this force causes acceleration but only of direction.
Everyone seems to have missed one force that's not obvious, buoyancy. There is an upward force acting you that is equal to the weight of the air you are displacing. Not much but it's there
That is true and it does exist. I'd just like to add there are just four fundamental forces. Gravitational, strong, weak, electromagnetism. These are the core forces.
*Force is an external agent that tends to change or changes the body's condition from motion to rest or rest to motion usually by pulling* *or pushing.* Learnt when I was 11 in my Nepalese school!
I liked this video like to hear what public thinks I would a said gravity is pulling me down but at the same time the earth is exerting a force of my weight up to keep me from sinking into the ground very cool channel man
@Chuukun1 it is true that the gravitational force acting on us has an equal and opposite reaction force, but that force is acting on the Earth, not us. It is the normal force that keeps us at equilibrium.
The normal force force is by no means the reaction to weight, an action-reaction pair is by definition a pair of force of the same magnitude, in opposite directions acting on two separate different bodies that are interacting with each other. Given normal force and weight are both applied on the same body, the are not an action-reaction pair. But that is a common misconception :)
Carolina Allende "The normal force Fn is one component of the force that a surface exerts on an object which it is in contact -- namely, the component that is perpendicular to the surface." -- John D. Cutnell & Kenneth W. Johnson (Physics Sixth Edition) I'm not sure how sorandom16 is incorrect. The human body is one body, while the Earth is the second body.
Soulsphere001 It's the component done by the surface, you said it yourself, weight is not exerted by the surface, but by the gravitational field. They do cancel out, but I insist they're by no means an action-reaction pair
Carolina Allende I'm still struggling to understand how the normal force is different from an action-reaction pair. The following may help you understand why I'm confused. "Newton's Third Law of Motion: Whenever one body exerts a force on a second body, the second body exerts an oppositely directed force of equal magnitude on the first body. ... The third law is often called the 'action-reaction' law, because it is sometimes quoted as follows: 'For every action (force) there is an equal, but opposite, reaction.'" -- John D. Cutnell & Kenneth W. Johnson (Physics Sixth Edition, p. 87)
+Mike Gregor That is due to the fact that the pressure inside your body is at an equilibrium with the atmospheric pressure. It is in said equilibrium unless that amount of pressure is greatly increased, like by diving to the bottom of a deep pool, you feel that your ears hurt, that is because your inner pressure is not at an equilibrium with the water pressure. Same when you go on an unpressurized cabin on a flight. The much lower pressure of the upper troposphere (the level of the atmosphere at which most passenger planes cruise) is much less than what your body has adapted, and the equilibrium is disturbed.
Well at the center of these forces is just 4 fundamental forces. Force as the equation says F=ma, is what is required for movement. Movement Is what makes us alive. All movement is brought about by force.
i learned that a force was a push or a pull in fourth grade, but i didn't think that was the real definition. I mean, we were ten and that definition sounds kinda oversimplified and dumbed down. it's nice to know that that is the real definition after all, and that a force doesn't have too difficult a definition.
everyone here in the comments acting smart with their F=ma explanations lol. if you weren't taught physics ever, you wouldn't understand (by definition) what a force is... so no need to act all smart. and no way in hell basics physics is taught in year 4 @Daniel Jay Santos unless you're in a private school for very bright people
no - force is merely an explanation for the desire of a particle (or a group of particles) to change translational velocity or mass. the mathematical definition of the SUM of all forces acting upon some control volume/surface is the change of that control volume's momentum over time. that is, SIGMA_F=d(m*v)/dt=m*(dv/dt)+v*(dm/dt) where dv/dt is the acceleration a (pretty sure this isn't correct for very high velocities). F=ma is only correct for bodies that don't deplete their own mass and that aren't travelling too fast either
TheAusrali Sorry pal. In Asia, we learn what force is in year 5. So you don't have to pretend to be a smartass. Knowing what force is doesnt make you smart. But not knowing the fundamental concepts as a grown up is a disgrace.
As you correctly said, that is the matematical definition of the SUM of all forces. The real question though is, what is the conceptual definition of A force?
I learnt basic forces in year 2 and extended (obviously when i say extended i mean i learnt more) in year 3 im inside a private school one of the best schools in its street (there are 2) im 11 years old and i know how forces work because of books i read. I know im being annoying but all im trying to say is that you don't have to have a private school to learn just read books. Please dont bully me im a kid who is being egotistical because 50% of the comments are and they are doing it so whats the difference if i do it
It's amazing how everyone agrees on "gravitational pull" that's pulling you downwards and no one mentions normal reaction force between us and earth. As if the weight is the only force acting downwards and somehow at the same time it balances itself.
The Gravitational, the electromagnetic,the weak and the strong force. Also there is a force working on you from all the molecules around you. (atmospferes?) And one of the most important: The force from the ground that works upwards wich is equal to the force that you work on the ground
Great video!! Your channel is an inspiration. I am gonna show it today to my yr8s in my Physics class about forces. One suggestion: how about getting more women with the right answers rather than men only? I am sure there are out there ;)
the symbol for surface area is A, it's only with units that you have to capitalise the names of physicist :) he wasn't using the letter p for pascal in his formula, he was using p to represent pressure, but i do think pressure is shown by the symbol P
The forces are exactly the same. The Earth pulls you with a force of (your weight here). You also pull on the Earth with the same exact force. It's just that the Earth is so massive (and by extension, has a LOT more inertia), the effect of that force is VERY small.
I'm pretty sure you spelled it right. Yep there is that word orthogonal again. I'm taking Calc 3 right now and we have to find the vector orthogonal to the plane, or the normal vector.
Inertia is what 'causes' an object to move in a straight line. An object at rest will remain at rest, and an object in motion will remain in motion along a straight line unless acted on by an unbalanced force. Centripetal force is a force toward the center of a rotating system, and it is a real force. Centrifugal force is the 'apparent' outward force, and is not really a force, but a result of inertia inside a rotating reference frame. Centrifugal force is sometimes pronounced 'centrifical'.
The ground exerts a force on the object that exerts the same amount of force on the ground. For example, If I push the wall, the wall pushes me back with the exact same force.
If you push something, you change its position. And its position is changing in a fixed time interval and that means it has got some speed ( or velocity). And in normal conditions, this 'something' has stopped moving (because of resistance) so we know that its 'speed' has changed in the fixed time interval, and 'change in speed' in this fixed interval of time is 'acceleration'. And this 'acceleration' can be a 'constant' or be a 'changing value'. So, approximately saying, Force is a concept ( an action you do) which changes the 'acceleration' of something. Here force = Pushing Force. I see Force, as a simplification of a more complex phenomena involving electromagnetic resistance, Friction, chemical interaction and some other phenomena which we cannot comprehend at once. Force is a word we created to simplify our understanding of our environment the same way 2 dimensional geometry was invented to reduce 'geodesics' and other 'hard to draw' things to simple lines, planes and a structure of Axioms, theorems and corollaries.
The force of the surface of the earth rebelling you from going down any further, it eleminates the force of the gravity and keeps you standing over the surface of the earth, and actualy this force is a kind of friction.
When we speak of force, we need to speak of an object with certain mass, and let's say, for example, that a force is the only one acting on this object. Now, this force is a physical quantity that is directly related to the acceleration that the object has and its inertia, and this relationship is force equals mass times acceleration. It's worthy to point out that a force is a physical quantity that has a direction, in other words, it's a vector. That's what I would've answered. :)
Pressure is force per surface area. p=F/A. If the wind was blowing with a pressure of 100N/m^2 or 100Pa (both the same unit of pressure) and you have a sail with an area of 2m^2, the total force acting on that sail would be 200N. F=p*A
it's as close as we will ever get , since we cannot explain why the quantum processes go on, we just observe them and make laws based on the properties.
The normal force balances the downwards force felt by gravity. The upward normal force is a result of the atoms at the interface between your feet and the ground, which are compressed together slightly. This brings the electrons of these atoms in proximity to each other, which results in electromagnetic repulsion, which is exactly enough to balance the force of gravity. Ergo the sum of the forces on a body are zero, and you do not accelerate in either direction.
There are tons of forces acting on us: Gravity is pulling down on our mass Normal force- ground pushing up against us Our clothes on us would be interacting with our outermost electrons, so electromagnetic Downward air pressure
You're actually lighter on the equator because the earth bulges slightly on the equator, (think of pizza dough as it begins to spin) and you are therefore farther away from the center of earth where gravity affects you less. Someone had a video about this, I'm not sure if it was Derek, Vsauce, or MinutePhysics...
gravity pulling me down, electromagnetic force holding compounds/molecules together giving me a upward force, as well as keeping me together, and pushing on me from the light hitting my body. nuclear strong force keeping my atoms together. and air pressure, which pushes on my whole body (although not sure if that considered a force). probably more out there i haven't named but thats all i know.
A force is a push or pull exerted on an object which causes it to move, speed up, slow down or change direction. A force can change the shape and size of an object. The forces acting on u is your weight, atmospheric pressure and normal contact force.
There's Electrical, Nuclear, and Gravitational forces primarily acting on us. This is what he was looking for. Now beyond this I'm a total laymen, but if I recall the nuclear force is the bonds holding the nuclei of atoms together, responsible for giving us the opposing force to the electrical force at their various energy states which is primarily based on the electron configurations of the atoms. From here the atomic or electrical forces take place applying various "pushes" or "pulls" to surrounding atoms and molecules creating the complex biochemistry and chemistry that makes everything we know and prevents objects from passing through one another. The whole earth is made of these bonds, and therefore the matter that makes you up and the ground you stand on creates the opposite force preventing you from falling to the middle of the earth by virtue of its electrical and nuclear forces repelling the matter you call yourself. Basically, while we have descriptions of HOW these forces interact, ultimately I believe, we are still incapable of explaining the precise mechanism, so once you've reached the level of electrical, nuclear, and gravitational pushing and pulling as your basic explanation, the only place to go is complex mathematics and a large theoretical body of physics that seeks potential as yet unproven explanations for the mechanism behind these forces. If I'm wrong I'm really looking forward to hearing where I've mislead myself =).
that comes under electro dynamics. it is a force but a very small one when it comes to humans. we do exert electromagnetic force but a very small one. there are people who can exert a greater electromagnetic force. hence telepathy. but in this case, if a human is standing still there's the normal force which goes upwards, there's the weight force which goes downwards. they cancel each other out since they are opposing each other.
@kinping Actually he's appeared on Catalyst where he's repeated some of the same concepts in his videos just interviewing different people. I hope he becomes a regular on Catalyst or does his own reporting, he's very good.
Physics (F=ma) test: “Without”applying the Energy from within you, choose an object of your choice, and apply only the Force or Net Force needed to push it away from you or pull it towards you. Please let me know if you’re able to. This is only a test. Thank you.
Without applying energy from me? Then I cannot. I'll have to give the object an energy. Yeah maybe we can give it an energy from something else like maybe a fan. But the ball will not get energy out of nowhere
A force is a representation of an effect. You can't touch or see a force. It's not something you can isolate in an experiment, either. It's an interpretation of measured results. Example: gravity. Newton thought it was a force, an attractive pull between two objects. But an equally workable explanation is that objects simply follow a straight trajectory though a deformed spacial geometry. Both explanations are consistent with measurable experimental results (though Newton's slightly less so).
"Force does not exist physically in the same way that an object with mass does. This means that force cannot make surface contact with an object, much less push or pull it. The initial cause of all bodies in motion originates from the applied energy (E), which creates the momentum (p) necessary to make surface contact with an object, thereby enabling it to push and pull. This concept is mathematically expressed as Ep or the equation Ep = ma. Force was originally used as a placeholder by Sir Isaac Newton because he did not know the true nature of this force." ~ Professor Guadalupe Guerra from Laredo, Texas c/s
The force on an object can be determined in various ways fx. the force of gravity on an object is F = m * g m = mass of the object. g = gravitational acceleration, it varies from place to place on the earth fx. its 9.82 m/s^2 at my location, and the force which the wind pushes on a wall with is determined by F = p * A A = the surface area of the wall fx. 10 square meters. p = the pressure usually measured in Pascal.
1. Gravity pushing me towards the center of the earth 2. The earth's crust pushing me away from the earth just enough to negate the force of gravity. 3. The earth's atmosphere pushing on my skin, keeping my blood from boiling, etc. 4. My muscles working to keep me upright. 5. Light from my computer pushing my skin ever so slightly. 6. Distortions in the earth's atmosphere pushing on my eardrums allowing me to here sounds. 7. Osmotic pressure allows my cells to keep their shape thus giving me my shape. 8. Peristaltic pressure keeps food moving through my guts. 9... A lot of other internal and external forces, I can't possibly list them all.
If you are describing the vector using Cartesian co-ordinates in a 3d space, then absolutely you can have a negative direction. And if you are describing the vector using an angle and a magnitude, you still need to use negative values to describe angles below the x-axis.
those older videos of yours are very cool, simple but informative. I've never seen them before, must be that new youtube algorithm coz they pop up in my recommendations
i remember these were the only kind of videos he made. Great work, simple and very informative. He's turned to more long winded philosophy it seems lately.
I just came back to old video 😁
you know this guy's philosophy actually works. Even i thought that gravity is the only force acting in the beginning in the beginning. But then when he started asking if there are any other forces i started remebering physics lessons in my school. kudos to your philosophy, Derek!
1:08 I hate when people start trying to sound smart when they really have no clue what they are talking about.
yeah...
Omg "it's just a theory..." "Nobody knows what it's really about" "it's thing indescribable thing that keeps us from flying off into space"
Please kick this person from whatever college she's on..
"It's just a theory"
JandCandO irony
Asking a philosophy/postmodernist/cultural theory student, questions on science is gonna elicit such a retarded response.
Better not ask someone who's not been tainted with such thinking in the first place.
Thank you for making this video. As a high school Physics teacher, I can tell you this works great to get students thinking... and to start a lot of discussion around free body diagrams and analysis of systems. Wonderful job!
You sound like a great teacher! Many physics teachers are really passionate about the subject.
Good day fellow physics teacher.
As a high school physics student I slept through this video
and the hour long lecture following the video
I love watching these videos, they make me feel like a genius
I've been using this as an intro when I teach forces to my 8th graders for 5 years now :) glad to find your channel and see that you are still making new content! That's awesome ^_^ keep it up man.
8th graders? Shame on us, brazilian people; thanks to our curriculum, we wont't see basic newtonian mechanics until high school.
@@GeovaniLopesDias thas nott good
Normal Force
Gravity (not really a force but it acts as one), normal force, friction, buoyant force, probably some tension, centripetal force...idk what else maybe I got em all.
What is it
@@isabelkloberdanz6329 How many centripetal forces have you included there??
@@isabelkloberdanz6329 also torque, electric force, magnetic force, and fluid resistance (idk if this is the same as buoyant)
@@kunalsaha8636 It is the result of Newtons 3rd Law
Are there anyone else from 2024 ?
Yes
Yess bro
Hello
Sure gravity pushing down
Atmospheric pressure pushing down
Sun light pushing down
And cosmic radiation passing even through the earth
is*
Oh... the burn against philosophy students!
+Taxtro I didn't even understand the joke.
What does it mean to understand?
To relate it with 'the things we memorized' in our past experiences. Because what we understand is what we have remembered from our past experiences.
Or simply said, Understanding would be finding an association between Theory and Practice or between different concepts. More simpler, Understanding is connecting the dots.
nah, many scientest know their stuff, but also will sound utter idiots in art, philsophy, or where they come from or their purpose of living... people should be modest. but they can not. that is the real force..
Hey man just wanted to remind that you have come a long way, congrats. Can't believe this was 10 years ago.
@Tossphate Yeah, I'm getting around to the 4 force video (or 3 or 5 depending on how you want to look at it). I know it's been awhile but I've got distracted with other things. Why can't you walk through walls is one I'd like to do...
FIRST Lol!
SECOND lol!
@@TrollDude3 who cares lol ?
@@blablablaj Joe lol!
@@TrollDude3 what type of beef is this💀💀💀
when standing up. we have :-
- gravitational pull which pull us down to the center of the earth.
- atmospheric pressure. a push (1atm)
- and a normal reaction force which is a push on an opposite direction of gravitational pull. - this force is important because it will make the resultant force , F = 0. so we can stand still.
-and maybe some friction which is a pull. if i was shaking or fidgeting or moving
You're forgetting radiation pressure
What force is Working on a Person falling from a building?
@@sauravraj5271 person falling from a roof has no force acting on him until the moment he slams into the ground
@MrTriple3D no that's wrong there is gravity acting on that falling body with respect to a person standing down on the ground without moving.
What you said is correct with respect to the body falling down or a body falling down freely along the the initial body .
The best part of interviewing people are the freaky answers. :)
Force is the measure of interaction between bodies. That's the best answer I've ever learned.
And twelve years later I agree!
Do people not take basic physics anymore? Unbalanced forces cause acceleration, therefore another force must be canceling the gravitational one. This is called the normal force.
Scooby Jim Doo not if they are not trained. Normal force, though, is the Earth's hold on you. It's just called that way cuz how its oriented normal toward the "flat" ground in which we stand
@@Raikaska false. Watch this video: th-cam.com/video/aJc4DEkSq4I/w-d-xo.html
I'm a little late but I want to say, that we are accelerating a little bit due to the rotation of earth. Changing direction of movement means accelerating, right?
Or am I wrong?
@@jonathanlange1339 if you want to get super technical and big picture. yes change of direction is acceleration. the earth (and therefore you) is constantly accelerating toward the center of the sun. this acceleration causes us to go in a circle (orbit) around the sun. without that acceleration earth would fly in a straight line away from the sun and we would freeze to death without the heat of the sun.
@@Raikaska no. It is the ground pushing up against you
I have watched this video before, and I'm watching it again now. It has been since 2014 or 2015 that I started watching Veritasium, and I love it.
@Tossphate I have another video that has Introducing Normal Force in the title
My answer would be there's the force of gravity and the equal normal force from the Earth. But that's only in Newtonian physics. A more accurate answer is the Einsteinian one, which is that gravity is a curvature of spacetime, not a force, so the only force acting on you is the normal force, which means you're accelerating away from the center of the Earth.
Actually, even if you are standing still, the friction still has an effect. Try to stand still on the ice and see how that goes :) It's called static friction.
Gravitational force,
The normal reaction of my weight
The centrifugal force
Force due to air pressure
And force from inside my body to ballance the air pressure
the gravitational force and the force of earth's surface pushing me up
I don't think the Earth is pushing you up. It's pulling you down, the upward force is you pulling the Earth up, and your body resisting the downward force with muscles and bones.
4 words..
a
push
or
pull
forces that acting on you atm:
-force of gravity (force on person exerted by earth)
-newtons third law tells us that you, the person, exerts a force on the earth that's equal and opposite
-theres a normal force exerted by the earth thats equal to the force of gravity b/c of newtons 2nd law stating that no a=equal forces
-windy day means air resistance, so the force of air
-again, the force on person exerted by the air means there's an equal and opposite force on air thats exerted by the person.
-static friction force also prevents you from moving, so newtons second law tells us that the force of static friction is equal to any other horizontal forces.
Ok first you don't have to include the forces *by* the person. And secondly I'd like to add on first point. Gravity also acts between us and every other thing around. The air, humans, animals, walls, etc all exert gravitational force on us
Force is rate of change of momentum with respect to time:
F= d(mv)/dt
Thus via the product rule:
F = v(dm/dt) + m(dv/dt)
typically we can regard the mass of an object as constant (ignoring things such as relativity and rocketry) so dm/dt = 0
so:
F = 0 + m(dv/dt)
dv/dt is the rate of change of velocity with time, i.e. acceleration
dv/dt = a
Therefore:
F = ma
Congratulations, you just derived newtons second law of motion.
:)
A change in momentum is impulse
As a physics student writing his thesis on a very similar question, I find this short video very interesting.
who cares m8
A force stems purely from the tendency of the universe to attain a lower energy state. Force is the quantification of this tendency.
Love your answer.
Anant Singh glad someone saw it ;)
If iam standing (without any motion)
1.gravitational force: which pulls me down
2.Normal force which opposes the body from gravitation
While motion (first 2 forces are necessary which I mentioned above and other two forces also necessary to move)
1.To move forward I need frictional force ,with out frictional force you are slipping (no grip)
2. Muscular force inside you
Don't forget about atmospheric pressure and radiation pressure ;)
I think a lot of us would look as silly if an expert in a field in which we're not acquainted asked us questions
I had thought that initially as well, but he mentioned that he was asking philosophy students (1:17). With that and the demographics of the interviewees in the video, I imagine he's on either a university campus or academic institution of some kind. There's (or was) a fair chance he'd run into someone who would be able to answer.
This is not a video about what forces are. It's a video about which two forces the presenter knows. What about the fundamental interactions (graviational, weak, strong, electromagnetic) that keep our atoms, protons, quarks together and prohibit them from disintegrating into who knows what? WHAT are those forces? Where do they originate, how do they work, how do they differ from matter? That is the question behind "WHAT IS A FORCE?"
0:52 FTW
1:08 Said the almso exact same thing in another video: "It's an indescribable thing that keeps us from flying off into space "
0:52 > 1:08 | 3:04 LMFAO
I love how he shakes his head like he's laughing at them.
they have a left lobe (or vise versa) dominant that is responsible for "soft skills" like language, social skills, communication skills etc. The other lobe is responsible for logic, abstract thinking, spatial vision etc - all needed for engineering or science.
..."and that should teach me to interview philosophy students''
ZINGGGGGG!
Gravitational Force, Force from the ground pushing up, and to be more complete these two don't exactly cancel (by about 3 newtons or so) because I am accelerating in a circle once per day. There is also air pressure squeezing me and my body pushing back.
Question!: Do you ever interview someone who knows the topic like a text book? i.e.: Did anyone tell you right off hand that Force was mass multiplied by acceleration?
A lot of people probably did. I mean, this is basic middle/high school stuff.
enthralling content
Friction, Gravity, Normal force, magnetism force, air resistant, electrostatic and LIFE!!!
OOh I got one like wait, why is it blue?
There are also negative accelerations. They are a necessary and absolutely valid concept. Some might call it deceleration, but in physics, it is all acceleration. Most of the time, acceleration in the direction of motion is positive, and acceleration in the opposite direction of motion (deceleration) is negative. It doesn't have to be that way. Like I said, as long as you are consistent, it doesn't matter. The results will be the same.
well the gravitational force doesn't pull me down to the earth, it pulls me and the earth toward each other.
That keeps the centrifugal force of the Earth's rotation from slinging me out into space.
Inside my body, there are the atomic forces at work, the strong force keeps the nuclei of my atoms together. The electromagnetic force is responsible for keeping me together at the molecular level, as well as keeping me from passing through other objects.
The atomic weak force is responsible for radioactivity, it is believed that it is also (at least in part) responsible for the transmission of smell.
Atmospheric pressure is largely another expression of the gravitational force.
All that, and that isn't counting the elector-chemical interactions in my brain and nervous system to tell my thumb to overcome inertia and fiction by unleashing potential energy stored in my muscles into kinetic energy to Swype patterns across my pocket computer's touch interface keyboard to compose and transmit this information.
+Franklin Allen Remember that the "centrifugal force" is a fictitious force and doesn't actually exist, its just an apparent force in a rotating reference frame. It would just be your inertia causing you to fly out to space if the force of gravity was suddenly removed. The only force involved in circular motion is the centripetal force, which points towards the centre of rotation. And gravity is what supplies that centripetal force, keeping you on the earth, and satellites orbiting.
+Alex Dlugosch you are technically correct, which is the best kind of correct. However, wouldn't the centripedal force also be just an apparent force and not an actual force since it is just an expression of gravity?
+Florin Toader I cannot find a link, it was a tidbit from an old episode of a science program on scent, I wasn't to say it was Nova, but it was a long time ago, also the narrator said it was theorized that radioactivity was responsible for certain aspects of certain scents, like part of the aroma of a banana was caused by the radioactive decay of the potassium in the banana. That without that reaction, a banana would smell much different, if at all.
+Franklin no centripetal force is not an expression of just gravity. If you have say a rope and a mass tied on it and you're swinging it in circles. Then the rope is transferring the centripetal force (through tension force) and pulling the mass to center, this force causes acceleration but only of direction.
what?
It pulls you down to earth, towards the center of it.
so glad this was our physics homework
Everyone seems to have missed one force that's not obvious, buoyancy. There is an upward force acting you that is equal to the weight of the air you are displacing. Not much but it's there
That is true and it does exist. I'd just like to add there are just four fundamental forces. Gravitational, strong, weak, electromagnetism. These are the core forces.
Is there? This confuses me as there isnt any air below us, so does the Archimidean law hold?
*Force is an external agent that tends to change or changes the body's condition from motion to rest or rest to motion usually by pulling* *or pushing.*
Learnt when I was 11 in my Nepalese school!
PS:Mathematically, Force equals mass times acceleration which is obtained by the Second Law of Motion proposed by Sir Issac Newton
One major force is the normal reaction force from the ground!!
I liked this video like to hear what public thinks I would a said gravity is pulling me down but at the same time the earth is exerting a force of my weight up to keep me from sinking into the ground very cool channel man
Weight
normal force
friction
@Chuukun1 it is true that the gravitational force acting on us has an equal and opposite reaction force, but that force is acting on the Earth, not us. It is the normal force that keeps us at equilibrium.
Gravity. And the reaction of gravity. To every action there is a reaction equal in magnitude yet opposite in direction.
The normal force force is by no means the reaction to weight, an action-reaction pair is by definition a pair of force of the same magnitude, in opposite directions acting on two separate different bodies that are interacting with each other. Given normal force and weight are both applied on the same body, the are not an action-reaction pair. But that is a common misconception :)
Carolina Allende
"The normal force Fn is one component of the force that a surface exerts on an object which it is in contact -- namely, the component that is perpendicular to the surface." -- John D. Cutnell & Kenneth W. Johnson (Physics Sixth Edition)
I'm not sure how sorandom16 is incorrect. The human body is one body, while the Earth is the second body.
it
Soulsphere001 It's the component done by the surface, you said it yourself, weight is not exerted by the surface, but by the gravitational field. They do cancel out, but I insist they're by no means an action-reaction pair
Carolina Allende
I'm still struggling to understand how the normal force is different from an action-reaction pair. The following may help you understand why I'm confused.
"Newton's Third Law of Motion: Whenever one body exerts a force on a second body, the second body exerts an oppositely directed force of equal magnitude on the first body. ... The third law is often called the 'action-reaction' law, because it is sometimes quoted as follows: 'For every action (force) there is an equal, but opposite, reaction.'" -- John D. Cutnell & Kenneth W. Johnson (Physics Sixth Edition, p. 87)
his videos improved drastically.
"the mouvement... and the atmosphere..." he stopped her too late
The videos are awesome. Could you also make a video explaining why forces do not cause motion but they cause acceleration instead ?
The ground has an upward force on you
That is called the normal force
Jack Taylor
Isn't that electromagnetism?
Jack Taylor there is no such thing as normal force
@@lazydreamer7745 im guessing you're not an engineering student or physics one.
that beauty at the end 3:25 has a special look on her face when she hears about forces pushing up.... ^^
The force of gravity, the normal force, friction, to say the least.
+Mike Gregor That is due to the fact that the pressure inside your body is at an equilibrium with the atmospheric pressure. It is in said equilibrium unless that amount of pressure is greatly increased, like by diving to the bottom of a deep pool, you feel that your ears hurt, that is because your inner pressure is not at an equilibrium with the water pressure. Same when you go on an unpressurized cabin on a flight. The much lower pressure of the upper troposphere (the level of the atmosphere at which most passenger planes cruise) is much less than what your body has adapted, and the equilibrium is disturbed.
Well at the center of these forces is just 4 fundamental forces. Force as the equation says F=ma, is what is required for movement. Movement Is what makes us alive. All movement is brought about by force.
i learned that a force was a push or a pull in fourth grade, but i didn't think that was the real definition. I mean, we were ten and that definition sounds kinda oversimplified and dumbed down. it's nice to know that that is the real definition after all, and that a force doesn't have too difficult a definition.
"no one really knows" My Goodness!
how do they not know such a simple concept we started learning about force since grade 6
Because knowing this stuff is useless, so most forget
everyone here in the comments acting smart with their F=ma explanations lol. if you weren't taught physics ever, you wouldn't understand (by definition) what a force is... so no need to act all smart. and no way in hell basics physics is taught in year 4 @Daniel Jay Santos unless you're in a private school for very bright people
no - force is merely an explanation for the desire of a particle (or a group of particles) to change translational velocity or mass. the mathematical definition of the SUM of all forces acting upon some control volume/surface is the change of that control volume's momentum over time. that is, SIGMA_F=d(m*v)/dt=m*(dv/dt)+v*(dm/dt) where dv/dt is the acceleration a (pretty sure this isn't correct for very high velocities). F=ma is only correct for bodies that don't deplete their own mass and that aren't travelling too fast either
TheAusrali my highschool teaches physics...
TheAusrali
Sorry pal. In Asia, we learn what force is in year 5. So you don't have to pretend to be a smartass. Knowing what force is doesnt make you smart. But not knowing the fundamental concepts as a grown up is a disgrace.
As you correctly said, that is the matematical definition of the SUM of all forces. The real question though is, what is the conceptual definition of A force?
I learnt basic forces in year 2 and extended (obviously when i say extended i mean i learnt more) in year 3 im inside a private school one of the best schools in its street (there are 2) im 11 years old and i know how forces work because of books i read. I know im being annoying but all im trying to say is that you don't have to have a private school to learn just read books. Please dont bully me im a kid who is being egotistical because 50% of the comments are and they are doing it so whats the difference if i do it
Gravitational force, and the normal force , which is essentially an electromagnetic force between our bodies molecules and the grounds molecules
i would have just pushed you and said thats force
It's amazing how everyone agrees on "gravitational pull" that's pulling you downwards and no one mentions normal reaction force between us and earth. As if the weight is the only force acting downwards and somehow at the same time it balances itself.
He could've easily asked them what stops them from sinking through the ground, and they would've figured it out pretty quickly I believe
"Every action has an equal and opposite reaction." Paraphrased from some dead guy.
Yeah I'm pretty sure that bill nye the science guy said that but he's still alive
@@andyvillaveces477 It was Newton who said this
The Gravitational, the electromagnetic,the weak and the strong force.
Also there is a force working on you from all the molecules around you. (atmospferes?)
And one of the most important: The force from the ground that works upwards wich is equal to the force that you work on the ground
same times the force beat you
like police haha haaha
Old but gold.
centrifugal force
aman martolia *triggered*
That's a pseudo force, not an actual one.
That's a pseudo troll, not a real one.
There is only the centripetal force; the so-called centrifugal force is just inertia.
Savage!!
+ air pressure + light "wind" + very little centrifugal force + your nice chanel is phushing on my brain :)
you do know centrifugal force doesn't exist right?
lol cringe af
Great video!! Your channel is an inspiration. I am gonna show it today to my yr8s in my Physics class about forces. One suggestion: how about getting more women with the right answers rather than men only? I am sure there are out there ;)
Electromagnetism is the force pushing you back against gravity. What's weird is it's way stronger then gravity.
the symbol for surface area is A, it's only with units that you have to capitalise the names of physicist :) he wasn't using the letter p for pascal in his formula, he was using p to represent pressure, but i do think pressure is shown by the symbol P
The forces are exactly the same. The Earth pulls you with a force of (your weight here). You also pull on the Earth with the same exact force. It's just that the Earth is so massive (and by extension, has a LOT more inertia), the effect of that force is VERY small.
I'm pretty sure you spelled it right. Yep there is that word orthogonal again. I'm taking Calc 3 right now and we have to find the vector orthogonal to the plane, or the normal vector.
Inertia is what 'causes' an object to move in a straight line. An object at rest will remain at rest, and an object in motion will remain in motion along a straight line unless acted on by an unbalanced force. Centripetal force is a force toward the center of a rotating system, and it is a real force. Centrifugal force is the 'apparent' outward force, and is not really a force, but a result of inertia inside a rotating reference frame. Centrifugal force is sometimes pronounced 'centrifical'.
Nice video👍
force is energy and mass. force is what stops you from flying off the earth. the bigger and faster something is the more force it has.
The ground exerts a force on the object that exerts the same amount of force on the ground. For example, If I push the wall, the wall pushes me back with the exact same force.
If you push something, you change its position. And its position is changing in a fixed time interval and that means it has got some speed ( or velocity). And in normal conditions, this 'something' has stopped moving (because of resistance) so we know that its 'speed' has changed in the fixed time interval, and 'change in speed' in this fixed interval of time is 'acceleration'. And this 'acceleration' can be a 'constant' or be a 'changing value'. So, approximately saying, Force is a concept ( an action you do) which changes the 'acceleration' of something. Here force = Pushing Force. I see Force, as a simplification of a more complex phenomena involving electromagnetic resistance, Friction, chemical interaction and some other phenomena which we cannot comprehend at once. Force is a word we created to simplify our understanding of our environment the same way 2 dimensional geometry was invented to reduce 'geodesics' and other 'hard to draw' things to simple lines, planes and a structure of Axioms, theorems and corollaries.
The force of the surface of the earth rebelling you from going down any further, it eleminates the force of the gravity and keeps you standing over the surface of the earth, and actualy this force is a kind of friction.
When we speak of force, we need to speak of an object with certain mass, and let's say, for example, that a force is the only one acting on this object. Now, this force is a physical quantity that is directly related to the acceleration that the object has and its inertia, and this relationship is force equals mass times acceleration. It's worthy to point out that a force is a physical quantity that has a direction, in other words, it's a vector.
That's what I would've answered. :)
Pressure is force per surface area. p=F/A.
If the wind was blowing with a pressure of 100N/m^2 or 100Pa (both the same unit of pressure) and you have a sail with an area of 2m^2, the total force acting on that sail would be 200N. F=p*A
it's as close as we will ever get , since we cannot explain why the quantum processes go on, we just observe them and make laws based on the properties.
The normal force balances the downwards force felt by gravity. The upward normal force is a result of the atoms at the interface between your feet and the ground, which are compressed together slightly. This brings the electrons of these atoms in proximity to each other, which results in electromagnetic repulsion, which is exactly enough to balance the force of gravity. Ergo the sum of the forces on a body are zero, and you do not accelerate in either direction.
There are tons of forces acting on us:
Gravity is pulling down on our mass
Normal force- ground pushing up against us
Our clothes on us would be interacting with our outermost electrons, so electromagnetic
Downward air pressure
You're actually lighter on the equator because the earth bulges slightly on the equator, (think of pizza dough as it begins to spin) and you are therefore farther away from the center of earth where gravity affects you less. Someone had a video about this, I'm not sure if it was Derek, Vsauce, or MinutePhysics...
gravity pulling me down, electromagnetic force holding compounds/molecules together giving me a upward force, as well as keeping me together, and pushing on me from the light hitting my body. nuclear strong force keeping my atoms together. and air pressure, which pushes on my whole body (although not sure if that considered a force). probably more out there i haven't named but thats all i know.
A force is a push or pull exerted on an object which causes it to move, speed up, slow down or change direction. A force can change the shape and size of an object. The forces acting on u is your weight, atmospheric pressure and normal contact force.
A force is an exchange of momentum between objects. And there are more forces acting on you than that, for example radiation pressure ;)
Wow!!! Thnx for this video
There's Electrical, Nuclear, and Gravitational forces primarily acting on us. This is what he was looking for. Now beyond this I'm a total laymen, but if I recall the nuclear force is the bonds holding the nuclei of atoms together, responsible for giving us the opposing force to the electrical force at their various energy states which is primarily based on the electron configurations of the atoms.
From here the atomic or electrical forces take place applying various "pushes" or "pulls" to surrounding atoms and molecules creating the complex biochemistry and chemistry that makes everything we know and prevents objects from passing through one another. The whole earth is made of these bonds, and therefore the matter that makes you up and the ground you stand on creates the opposite force preventing you from falling to the middle of the earth by virtue of its electrical and nuclear forces repelling the matter you call yourself.
Basically, while we have descriptions of HOW these forces interact, ultimately I believe, we are still incapable of explaining the precise mechanism, so once you've reached the level of electrical, nuclear, and gravitational pushing and pulling as your basic explanation, the only place to go is complex mathematics and a large theoretical body of physics that seeks potential as yet unproven explanations for the mechanism behind these forces.
If I'm wrong I'm really looking forward to hearing where I've mislead myself =).
A force was once what sparked the big bang. All hail Force.
that comes under electro dynamics. it is a force but a very small one when it comes to humans. we do exert electromagnetic force but a very small one. there are people who can exert a greater electromagnetic force. hence telepathy. but in this case, if a human is standing still there's the normal force which goes upwards, there's the weight force which goes downwards. they cancel each other out since they are opposing each other.
@kinping Actually he's appeared on Catalyst where he's repeated some of the same concepts in his videos just interviewing different people. I hope he becomes a regular on Catalyst or does his own reporting, he's very good.
Physics (F=ma) test: “Without”applying the Energy from within you, choose an object of your choice, and apply only the Force or Net Force needed to push it away from you or pull it towards you. Please let me know if you’re able to. This is only a test. Thank you.
Without applying energy from me? Then I cannot. I'll have to give the object an energy. Yeah maybe we can give it an energy from something else like maybe a fan. But the ball will not get energy out of nowhere
Which is caused by the repulsion of the electrons both on our boots and the ground. Derek made a video about this. I forgot which one.
Some types of forces;
Weight
Normal reaction force
Frictional force
Air resistance
Water resistance
Gravitational force
@Bradley Davis Strong nuclear force acts on atoms (holding them together). The answer to his question is 2: normal force and gravity.
1-gravitational
2-normal reaction
3-frictional force
4-if your tilted then their components.
Spartance
5-Buyancy
6-I do not know how to Buoyancy
A force is a representation of an effect. You can't touch or see a force. It's not something you can isolate in an experiment, either. It's an interpretation of measured results. Example: gravity. Newton thought it was a force, an attractive pull between two objects. But an equally workable explanation is that objects simply follow a straight trajectory though a deformed spacial geometry. Both explanations are consistent with measurable experimental results (though Newton's slightly less so).
"Force does not exist physically in the same way that an object with mass does. This means that force cannot make surface contact with an object, much less push or pull it. The initial cause of all bodies in motion originates from the applied energy (E), which creates the momentum (p) necessary to make surface contact with an object, thereby enabling it to push and pull. This concept is mathematically expressed as Ep or the equation Ep = ma. Force was originally used as a placeholder by Sir Isaac Newton because he did not know the true nature of this force." ~ Professor Guadalupe Guerra from Laredo, Texas c/s
Force is essentially the rate of change of the velocity of an object times the resistance to that acceleration. And in this case that its mass
The force on an object can be determined in various ways fx. the force of gravity on an object is
F = m * g
m = mass of the object.
g = gravitational acceleration, it varies from place to place on the earth fx. its 9.82 m/s^2 at my location, and the force which the wind pushes on a wall with is determined by F = p * A
A = the surface area of the wall fx. 10 square meters.
p = the pressure usually measured in Pascal.
1. Gravity pushing me towards the center of the earth
2. The earth's crust pushing me away from the earth just enough to negate the force of gravity.
3. The earth's atmosphere pushing on my skin, keeping my blood from boiling, etc.
4. My muscles working to keep me upright.
5. Light from my computer pushing my skin ever so slightly.
6. Distortions in the earth's atmosphere pushing on my eardrums allowing me to here sounds.
7. Osmotic pressure allows my cells to keep their shape thus giving me my shape.
8. Peristaltic pressure keeps food moving through my guts.
9... A lot of other internal and external forces, I can't possibly list them all.
If you are describing the vector using Cartesian co-ordinates in a 3d space, then absolutely you can have a negative direction. And if you are describing the vector using an angle and a magnitude, you still need to use negative values to describe angles below the x-axis.