Added: 4 years ago
From: khanacademy
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  • haha.. face massage.

  • RECOIL!!! :)

  • lol.. your awesome. 

  • if you were in space though the ball and you wouldnt weigh any thing so it wouldnt count??

  • For the gun example the term is "recoil"

  • Haha, this video was great, funny and very helpful!

  • It's every action has an equal and opposite reaction.

  • when I think about these things.. i go crazy..my lil brain would just explode..newton..why why why!!! why did u need to think abt all of dat!!!!!!!!!!!. we poor ones have to study this cuz of u. its really hard for me to blyv this law.. the others make sense. bt this one.. uhhh... godd!! . studying= student + dying.!!!!!!!!!!!!!!!!

  • A bouncy ball is a great examplw that rlly helped me!!!

  • thanx man You helped me study for a physics test!

  • "I guess we could say, punching the hand, or - oh no we're not using the violent" lol

  • the force of the gun is called recoil

  • these stuff are way easier in arabic xD

  • dude you are amazing! I understand the third law noww!! I love the bullet and shoulder sample!! dude i love you!!! thank you so much!!!!

  • Hahaha

    i like ur drawings

    and what if the earth wasnt round and was flat?

  • 2:02 MINECRAFT!!!!

  • wht was the date when the law was crated or found

  • @mandm1997 Newton's laws were published in 1687 according to wikipedia's page on Isaac Newton.

  • What program did you use to create this video? It was very good. 

  • @MsDarla89 Paint. And he crops out the other part.

  • What does the man have between his legs at 6:30? lol!

  • @ivs511 idiot

  • thumbs up if u tried to put ur head upside down when he talks about the earth falling towards you ;)lol

  • @kristijanadrian The higher-derivative phenomena like 'jerk' (linear) and 'transverse force' (rotational) are of interest only in 'man-made' situations such as machinery (guns, cam-followers, etc.). There is no fundamental physical law which involves them. That is, the known 'structure' of the universe does not impose excessively complicated relationships between its fundamental units.

  • @kristijanadrian It is s^2 largely because this parallels the form in which time appears in the differential equations of motion. There is indeed no end to the orders of derivitives of a given motion (provided that that motion is sufficiently 'complex'). Similarly, there are an infinite number of fictitious forces beyond 'centrifugal' and 'Coriolis'. However, these higher derivatives (and 'forces') of linear and rotational motion are rarely named and are irrelevant to fundamental physical laws.

  • In general, this vid tends to introduce the sloppy thinking that continues to make physics a closed book to most people. For instance, why does he refer to 'weights' right after suggesting that objects are in outer space? A serious underlying problem is that Newton's laws refer to POINT particles. By using compound bodies as examples, he is storing up conceptual difficulties (and apparent paradoxes) which will impede the serious student later.

  • I think of an good example. If a person stands with one foot, and pushes on the wall. He/She will fall backward. The amount of force the his/her arm pushes will receive back to the person.

  • see listen if your applying force on a tree and tree is not moving how will that apply force on your hand ?

    

  • @LuCnEoN The tree does not have to 'move'; the elastically compressed surface layer will provide the reaction force. But you have in fact hit on a serious defect in this teacher's approach (as I have pointed out elsewhere): one should use only point-like particles to explain Newton's laws. The use of extended and compound bodies complicates the situations in ways that very few school-teachers are capable of explaining properly.

  • Howcome,no one ever points out that Newtonian vs. quantum is pretty much perpendicular? The third law is open ended if its a rocket capable of breaking the earths gravitational pull. Once out in space (up) its free of earths gravity. Pushing your car forward on a flat surface will eventually be overcome by friction. Does this make sense?

  • @newage4energy Why the mention of 'quantum'? That makes no sense.

    The rocket NEVER escapes the gravitational pull of Earth. However, once the rocket achieves the escape velocity gravity can never pull it back down even though the third law still applies.

    If the same rocket were to be placed in space, an 'infinite' distance from Earth and with no initial relative velocity, it would eventually hit the Earth with a velocity equal to the escape velocity. Physics: beautiful but counter-intuitive

  • This is a terrible way to teach Newton's 3rd law. No evidence whatsoever is presented to convince students of the Newtonian force pairs, and no logic is used to examine what would happen if there *were* unbalanced forces in the universe. Nor is there any talk about *types* of forces. Example--is the floor pushing up on you with a force of 150 lbs? Yes. Is this due to Newton's 3rd law? No. Explain why not, based solely on this video.

  • @wiscgaloot I see (belatedly) that you agree with me. I always feel that the first law of thermodynamics is the best way of getting Newton's 3rd law through to students. Unfortunately, school-teachers have an obsession with teaching laws in historical order, and philosophers are too fond of claiming that that argument is circular!

    I was recently arguing with a professional aeronautical engineer; he was clearly confusing the 3rd law with the condition of mechanical equilibrium throughout!

  • "I think I'm going too violent with the examples, but we're talking about forces, so maybe violence is justified here" haha, Sal is so funny xD

  • hehe, been listening to Sal for so long i had to go see what he looked like. funny little Indian looking dude. he's all animated just like he sounds like he would be.

  • If every action has an equal and opposite reaction then what is the action which causes the reaction of gravity? Newly created energy! Accretion causes things to collect in a vacuum. When the object reaches 100 miles in diameter the pressure at the core heats to around 2400 degrees causing the material to turn molten. The new energy radiates outward like a spherical wave. This is the action which causes the equal and opposite reaction of gravity. The wave is continuous as is gravity coming in.

  • @GateMessenger What drivel! You obviously read (popular) science books, but fail to understand them.

  • @flowerbower Well then if you're so intelligent tell everyone what causes gravity.

  • @GateMessenger Bodies follow geodesic paths in curved 4-dimensional space-time. In three dimensions, the consequent observed motion is interpreted as being due to a force, i.e. gravity. This explanation is far superior to previous ones such as the particle theories of Newton and LeSage and the wave theory of See.

    Only crackpots now adhere to such theories, or invent crazier ones.

    BTW, I have to tell only you this. I am pretty sure that 'everyone' else here already knows it.

  • You leave that tree alone.

  • the term for the gun is called kick

  • @PhxPride1 A scientist would say, 'recoil'.

  • impact and absorption would also be taking effect.

  • A donkey which has heard of Newton's third law but not understood it very well refuses to pull a cart attached to it because it argues that: ' If i pull on the cart with a certain force, Newton's third law would imply an equal but opposite force, which would then mean that the total force on the cart is zero, and so it will not move. so why waste my effort? I won't pull'. What's wrong with the donkey's argument?

  • @harisonh1 The flaw is that the net force of the cart is not zero. You are the only one acting on the cart. Action - reaction pairs do not act on the same body. Thus the cart will move.

  • Another question: When does a bullet stop accelerating? The instant it leaves the barrel? It has to, no?

  • @Chrisbajs Even in the barrel it would stop accelerating due to air resistance.

  • @Chrisbajs It stops accelerating when there is no net force exerted on it.

  • This would be better on ice-skates!

  • It likes violence - It keeps my attention when I'm gettin' learned.

  • the total net change in my grade is 0, because the positive force of me knowing my shit after watching these videos is equal and opposite to the negative force of me skipping class because really why bother when I can just learn my stuff here

  • This law helps to understand why 9/11 was an inside job.

    The North tower is a prime example. The top of the building cannot crush the bottom half WITHOUT SLOWING. As anyone can see, that does not happen. There is NO RESISTANCE. The NT falls at freefall speed, with no resistance, at the speed of gravity. If you leaned anything from this video, you know that it is impossible. ERGO, explosives moved the parts of the building that would of normally provided resistance to the top. GREAT VIDEO

  • @FreedumbFighter28 Your troll logic is flawless and cannot be questioned.

  • @HerlockSholmes123

    :-)

    Back handed compliments are accepted.

  • @FreedumbFighter28 Well, I hope my sarcasm didn't offend you in any way :)

  • @HerlockSholmes123 no no, as a matter of fact, it is quite appreciated.

  • @FreedumbFighter28 Sarcasm?

  • @FreedumbFighter28 osama's dead! lol

  • @gdawgfernandez yea, maybe now we can see the secret evidence of his guilt,huh? Ten years now, been waiting a looooooong time to see the proof he did 9/11, Will they show us just how they knew he did it 6 hours after 9/11, even though we had NO advance warning. I mean, some REALLY good police work went on behind the scenes.They must have some really compelling proof he did it to launch a year war. Now that he is dead, the whole world is waiting for all this empirical evidence.

  • @FreedumbFighter28 You seem to have forgotten the concept of momentum (mv): the velocity may decrease but the mass of falling material is constantly increasing as more and more debris is created.

  • thanks for the vid! i really like it! it helps me to understand physics easier

  • This is the physics behind the propulsion of a rocket!

  • Didn't know your bodymass was as much as Victroria Beckhams, but that's fine . . . until you die.

  • trololololololll!

  • how dare you make fun of newtons principles like that with guns and shit! its just a bad example of one of the greatest discoveries made by newton and you cant do any fucking thing but crap

  • @1Mametchi1 the heck is ur problem?

  • @RoflJoker1994 whats urs? you cant even get a PROFILE PICTURE

  • @1Mametchi1 hahaha. =P

  • @1Mametchi1 Oh shut up, Khan's a fantastic teacher. You're just an overly sensitive moron.

  • @blo0dyme There is nothing more dangerous than a 'good' teacher. The bare concept of 'teacher' carries no moral imperative. This one makes it sound clear and simple to you, but is actually leading you astray. However, you will not find that out unless you continue to study physics. So, is someone who passes his class really 'educated'?

  • Okay, let's say we have ..., i don't know... a knife? Yes. A knife. And let's say that the knife is.... i don't know... stabbing a bystander.  Okay. There's the knife there (draws knife) and there's the bystander. Now let's say that the knife is exerting a force of 10 N just so that it's not so violent. The bystander's not happy.

  • Ow, I punched a tree!

  • so i have a fist and its punching someones face.... lets no make it so violent

  • lmfao...massaging trees and physics...i love this

  • I have a fist, and it is punching someone's face, and they are not happy.

  • @leifman7 haha funny

  • aww i love sal, very violent mind though - first he's throwing ppl off of buildings and now he's punching ppl in the face? lol x

  • 6:20 the ball don't weight 1 kg it's mass is 1kg.

  • I say the rocket, it exerts a huge force toward the ground in order for it to lunch/take off toward the sky! :)

  • @Darkcurse101 not really the rockets engines exert a force on the gases they expel from the rear of the rocket ,and these ejected gases exert an equal and opposite force on the rockets in the forward direction and this reaction force exerted on the rockets by the gases is what accelerates the rocket forward

  • I have no idea why, but this video always makes me laugh. :)

    But I love the examples, it makes me understand,

  • considering you are in deep space and there would bot be external friction or air resistance, would you not remain stationary and the ball accelerat continually at 9.8ms^-2?

  • @cloudftw93 No, as you said "deep space implies no gravity, no friction, no air resistance no external variables" what counteract the less obvious effects of forces we experience here on earth such as the equal and opposite reaction force a ball exerts on a person when he pushes against it.

    Because a force is also exerted on him he will move as well as the ball, in the opposite direction and this is noticalble in deep space due to the abscence of those opposing forces.

  • why doesn't this apply to chris brown and rihanna? ;)

  • sorry for my bad whriting

  • no no NO! dont do bad exemple like at 5:50 the sorwds, it is hold from the tow sides, will the other one isnt, it makes a complet difference(you dont now the word recoil? lols.wy did i evan listen to your full vid? and by the way about that its also cus the gun absorbs the recoil and that if you cut the berrel a bit, theres gonna have less recoil, but also less power and accruacy, cuz theres allways an explosion wen the bullet gets out of the chamber, but the shocwave stop a little but to pouch)

  • "Imagine it was a tree you decided to massage".  Ha.

  • LOL awsome nice nice nice. "fist punching face with 10n wait wait lets to make this less violent" LOL

  • It is really helpful, now i fully understand how this law works, Thankx Uploader

  • HIS FACE WENT INTO MY FIST!!

  • awesome

  • At 9:15, it's recoiling of a gun

  • at 9:16, ir's recoil

  • interisting

  • hey is it true???? about d sword?? they will both brake?? if the same force apply in both sword ?? ohh i dont think so...

  • @07jayus

    No he's right , both swords will break.

  • hey,i just wanna ask if lbs is a unit of force,i thought it is a unit of mass like kg...

  • @10mrRight10 lb is a force, not mass. You have to divide lb (aka pound) by 9.81, the acceleration due to earth's gravity, to find the mass. Kg, on the other hand, is the mass.

  • Comment removed

  • hey khan!!ur the newton of the century!!good tutorial job!!

  • Really helpful thanks! these videos are also more entertaining than a regular physics class in school! great job!

  • thanx man!! it really hlped for my experiment which i have to do tomorrow!! thanx a lot!! :D

  • lol awesome face

  • 8:28 the term is "recoil"

  • Wow that was 9minutes? and i was paying attention the whole time? This is so much better then school, thanks man, really helped.

  • Or messaging a tree xD hahaa

  • So if you do a hand-stand you are lifting the Earth; LOL

  • erm sal its called recoil ;D the gun thing....

  • what is the purpose of school now lolz

  • GREATEST SCIENTIST EVER.

  • i was waiting for you to say massaging some wood XD. i would have loled

  • What is the scientific definition of "an object exerting force on another object"?

  • nerds i needed this for a sicence project!!!

  • Surely with the gun example, it is the fact that the explosives in the cartridge are, when ignited, producing force in all directions, rather than the bullet itself causing the recoil?

  • face/tree is not punching back. in motion, the hand is + because it is in motion, the face/tree is zero because it is motionless. earth and people don't pull each other, that's a sensory illusion.

  • @99mees radiation=gravity. only an object in motion PRODUCES/GIVES OFF force. the neutral face will remain neutral until the hand punches it.

  • @99mees radiation gives us gravity not earth.

  • You should do a shot gun being shot then pushing back on you

  • Where did you get your astounding artistic abilities sal?

    Awesome videos by the way, I will sacrifice my first born child in your honour.

  • @louza8 In case you're being sarcastic he was actually a cartoonist in college!

  • @MrPlender lol brilliant. much respect to sal.

  • TErd!

  • pretty coooool!

  • for the gun example, the word ur lookin for is "recoil"

  • @mgsolo1616 COD for the win

  • the bullet example at the end was on point!

  • but dude the swords can never be the same as each other... the atoms in it can`t be arranged to the same position at the same time ain`t it? :)

  • nice))))

  • You taught me something

  • i have a fist...and it is punching someone's fiss...lol!!!

    sorry...

    what accent?

  • @SilentSnipershot troll!! You need to learn to defend yourself without vulgar usage.

  • The gun term is recoil I believe.

  • To NAIL THE POINT QUICKLY, u get hurt the more bad you hit, 'cause what you hit gave u the same force back.

    Forces acts in pairs.

    Quickie, done, within 10 seconds?

    THUMBS UP please and REPLES

    Thank you

    Nikhil

  • your incredible

  • very nice "tutorial".

    Good what you're doing for people who have trouble with physics

  • AWSOME .

  • lool They are happy XD

  • no man u don't weigh 50 kg that is ur mass

  • o.O.....you do sound like an illiterate inane fool.. you cannot assert me from correcting him. so why are you wasting your time posting garbage on youtube?? that is just pathetic

  • im kidding dyke i was on a school computer when i did this with a friend

  • so in space, you fire the gun, you move as fast as the bullet backwards? :D

    i wanna go to space na0~

  • Um, no, because you're mass is far greater than the mass of the bullet.

  • Yikes, your*

  • You would accelerate, but at an acceleration proportional to your mass.

  • @zomgbbqwth thats funny I wish it was true maybe maybe not but remember what is a bullet? It is defined as a projectile so if you fire off a 400 mm which is close to he sizeof the average woman, then you might go just as fast

  • if you tear a paper with your 2 hands, it wont tear at 2 different places~ so if you use 2 same swords hit each other at the same increasing force, only 1 will break~ they both wont break at the same time even though same force is applied in the same opposite direction~

  • bruce lee said "why break boards and bricks and shit when they dont hit back..."

    so the third law doesnt apply~ lolz~

    nah~ juz messing with you~ :D

  • wow you explained it really good !! :)

  • sal, your examples are either morbid or violent. lol.

  • LOLLL yes

  • thanks. now i understand my skool work.

  • the term you are looking for is recoil.

  • Comment removed

  • ROFLMAO!

  • Ah, because there are tiny forces pulling everything together, during the example you had where you had someone falling to Earth, and you said, "Maybe the Earth is 'falling' to you." This really helped me out. Thanks.

  • 3:10 I cracked up! good lesson though...

  • i used this for my homework

    Thank You

  • wow, man, this really helped. I drew this subject on my exam last spring, and in a few days I'm trying physics again because maybe I could get a better grade. My bad explanation of Newtons third law was the reason I got C instead of B.

  • I think the violent examples were good just because it wasn't a ball hitting a brick wall, which is what I expected. :) Thanks for all these videos, Sal!

  • but wen u push on sum1 head and it has a EQUAL force it moves the force is not always equal it dnt always have a equal and opposite reaction u drop a bowling ball on ground and it breaks the floor and goes through how is the force equal the bowling ball force is greater y did it go throw moleules aint as tightly packed together and it dnt always push back the same depending on the mass depends on the force so how is it always equal or maybe im just stupid

  • The opposite force is allways equal. However the mass of the bowlingball, and the mass of the ground and the density of the bowlingball and of the ground is different. Still they push on eachother with equal force.

  • thanks this really helps!! keep it up!!

  • so what about a plane hitting a steel tower? what would happen then?

  • It would fall.

  • what would fall? the plane as it hit?

  • Depends on the structure of the tower and where it hits it, its different forces on different places. (I'm a Civil Engineer). So it depends which tower you are talking about.

  • im not really talking about any specific building. just a steel tower. 1,000 foot. and my guess is if a large boeing jet hit the wall the plane would just explode against the tower right? or would it slice right through without even breaking off its wings and come out the other side?

  • Are you talking about the World Trade Center? If you do then yes, that's correct. The steel tower could have handled that and not fall. I have read that the Civil Engineers who build it say, there must have been bombs placed in the tower that would help it fall.

  • 1st im not on about the building falling. im on about what would happen to the plane upon impact?

  • Force that pushes you back when firing a weapon is called recoil.

  • I think the easiest way to explain this is to hold a piece of paper against a wall with say 10N. If the wall weren't exerting 10N on the paper and your hand, the paper would simply fall. Try it, it makes more sense if you see it. Just hold the paper there forget about friction for the moment, and it's quite easy to understand.

  • Is this why people get tired. By this I mean if your punching a punching bag your getting the force you just exerted on to the punching bag down your arm. or is the arm getting tired just because of the forward and backward motion of punching?

  • game1208: I'd say both. Because moving your arm needs force to displace the air while when you punch a punching back, it also exerts a force on your fist and arm.