More on Newton's third law | Forces and Newton's laws of motion | Physics | Khan Academy

[@simranjoharle4220]

I always thought that equal and opposite forces should cancel each other out and nothing should ever move if Newton's third law is true....but this doesn't make sense in the practical world so I never believed the law was true until now....tnx a lot

[@dontblink20]

Simran Joharle i had that same misconcept and thnx to this video i got it

[@johnfox9169]

That is the BEST explanation of the third law I ever encountered. Great job and thanks!!

[@asadraza3149]

Even the most reputed channels for physics confused the problem of weight and normal reaction as an action reaction pair model. Thank you for explaining it so clearly.

[@mojo6689]

i feel so smart right now

[@lanf6188]

same

[@austin16377]

moses m lol

[@afsheentahira3241]

omg me rn lmao

[@handsonfire6113]

I feel tired

[@subhasissarkar1357]

Thank you so much for clearing our misconception. I had the same misconceptions that were being discussed. Thank you.

[@AdamTheWeeb]

This was EXTREMELY helpful. Like you have no idea how helpful. I will probably not fail my physics test today now. Thanks c:

[@chenchuanshui6858]

Thank you very much You solve my problems that confused me for a very long time

[@frankivinstutoring3775]

Best explanation of this confustion I've ever seen. Thanks!

[@feranmiadeyemo2362]

Wow. I have been enlightened. Thank you so much Professor.

[@mustafar]

David explains really well!

[@YusufKhan-ec8hj]

Professor David explaining Newton's laws misconceptions like playing Pacman!! (kudos)

[@aditimitra8040]

I have a question. If we push a block lying on a table, we apply an action force on the block. So, the block must also apply an equal and opposite reaction on us. Then, the two forces must cancel each other and there must not be any acceleration. But this doesn't happen. If we push the block too hard then it moves. So how does this happen?

[@jfhameem1532]

why this thing is so cool??...Really loved it.😘

[@afsheentahira3241]

7:34 “this example drives ppl crazy for some reason” LMAO (i was at first too lol)

[@Talentist-if4ge]

The MOST underrated channel of the decade

[@mdhassanjahangirkhan5756]

Best explanation ever I got

[@fzka_]

Okay, this answered a lot of my questions regarding to N3L! Thanks to Khan Academy

[@ossabellator13]

Thank you for this video. Most clear explanation I've seen.

[@lizarose3095]

Fantastic video!

[@ruanoosthuizen6084]

Interesting. So, in sprinting, to sprint faster, how would this theoretically apply? It's obviously not just "put more force knto the ground in the right direction" is it?

[@lychee4031]

thank you for the clarifications!

[@Kanari152]

THANK YOU VERY MUCH!

[@ppscphysicspreparation2626]

Thnku so much, i was highly confused till i watched this

[@ธวัชชัยก้อนเพชร-ศ1ห]

0:50 bruuuuh💀💀💀💀

[@huntergirl7275]

I think there is a problem with your box on the table example. How can the box be pushing down on the table (F(subTA)), but pulling up on the earth (F(sub EA))?

[@ЮлияВиноградова-ю6и]

I thought about it for a really long time and watched video three times ). And I realized that there are no mistakes. Earth attracts box A that's why the box need to resist that's why F(sub EA) is pointing up. On the contrary, table doesn't attract box A, but box A pushes down to the table F(subTA). So that's all right.

[@robertjr8205]

@@ЮлияВиноградова-ю6и yea the box is being brought toward the earth. So it should be the force exerted on Earth by box A rather than the way he wrote it. And the green one should be the force exerted on box A by the Earth. The earth is pushing up against the box. The way he wrote that contradicts the sand example that was done in another video and the wall kicking he did in this video. Edit: Nevermind. You are right. My bad. This one bothered me a lot

[@iwishifiwasaneconomicsnerd9648]

good explanation.

[@geeksahilthakur]

sir we know that F = ma then how will the wall apply force if you kick the wall as you have shown in your example ?

[@agent-sz2qj]

the mass of the earth is approximately 5,972 × 10^24 kg, so if i excert a force of for example 50N on the earth , the earth will have an acceleration of a= F/m = 40N/5,972 × 10^24 kg = 8.372*10^(-24), even though it's a very small acceleration, can i say that i've moved the earth ?

[@YaserSamin]

the silence breaker Yes you can say you moved the earth but in reality it's not going to move. Why it is not going to move? You should know it by now.

[@agent-sz2qj]

because the sun is also exerting a gravitational force on the earth ?

[@YaserSamin]

the silence breaker Let's not make it complicated. The force that you Exerted, the Earth is going to exert the same force on you. Relative to Earth and yourself only, Newton's Third Law is going to act. However, your force won't move the Earth because Earth is a huge body and it's impossible to make it move with such little force Only the sun can exert a force and make the Earth Move. Earth exerts the same force on Sun but the sun remains in it's position because of how large it is compared to Earth.

[@rajanesaki9051]

Actually it will move if you are the only organism living alive....or else the will be other people who'll be cancelling out what you've did....from the other side...

[@legendic2755]

why do you want to know if moved the earth just live your life

[@DaniilRogers]

This explanation makes a mockery of my high school physics teachers😅😂

[@thxdts1999]

Many thanks for the video very pertinent

[@leos9682]

how does the force of the table itself to the earth affect the box? or does it not matter?

[@agent-sz2qj]

for example , if i were in space and there is no gravitational force or any other force, and an object with the mass of 0.01 Kg hits me with a force of 0.1N, then i will exert on it an equal opposite force, it's acceleration would be a=F/m= 0.1N/0.01kg =10 m/s^2, is that correct ?

[@ranjanchauhan4455]

Great..

[@phenomenalphysics3548]

10:06 but the earth is actually moving toward the object when it falls with respect to object

[@robertjr8205]

yea

[@THEMATT222]

So Newton's third law is a scientific version of Karma

[@THEMATT222]

@Moon Deccans yeah, lol

[@kategothberg4976]

God bless you my man

[@tonyhill2318]

Holy crap you're beating a simple topic to death

[@sharonsolana]

I'm confused. I have to watch this again.

[@danielsengal8431]

I thought I new newtons 3rd law but I didn't, thanks for the up grade

[@baskaranbaskaran5283]

When we drop a object from a certain height from the ground. It strikes the ground but not attained the height of where it dropped .is Newton third law is wrong ? comment about it

[@ihatetobethatguybut7175]

I think that the "opposite" force doesn't include the Gravitational Force, or maybe it has something to do with Newton's second law, specifically the Mass of an object

[@malaikashroff7608]

That has nothing to do with force. That’s because of energy. The earth has a force on the dropped object (gravity) and the dropped object has a force on earth. That last force doesn’t result in much acceleration by earth Bc earth has a large mass.

[@sathibabu9365]

Sir but action and reaction is not equal in the water but you newton told that action is always equal to reaction why ❓

[@sathibabu9365]

@Moon Deccans when I entered into water I am applying a force with my foot but the water not applying same force why

[@sathibabu9365]

@Moon Deccans sir that only l am telling newtons 3rd law has to obey for every action has to be a opposite reaction but water is not showing reaction on mee SO, newtons 3rd is not obey there

[@sanjakader9011]

the force on earth by A, pointing up, what force is that?

[@rabblay9073]

Sanja Kader Normal force.

[@fionagreen9322]

its your own personal gravitational force

[@phenomenalphysics3548]

@Rimjhim Mitra Exactly! I see them LITERALLY EVERY WHERE!!!!

[@Dr.Bright]

at the end of the video a dog barks Edit: 13:04

[@phenomenalphysics3548]

It is surely some other sound lol

[@ricaramirez5411]

How do you know whether the force is the F(color green) or the -F(violet)? Sorry I'm a bit confused hehe does it matter which is which?

[@brunoramirez2602]

yaeh, it doesn't matter, it just the opposite force. You could call -F(violet) F, and then F(green) would be -F.

[@ricaramirez5411]

thanks!

[@homemadesauce6153]

What about a rocket dou. It's on the same object

[@s.mishra5595]

Maybe like rocket exerts force on the particles and they exert force on the rocket

[@legendic2755]

I understood nothing, you just made me more confused, I hope sal created this video

[@weebz4748]

David > sal

[@phenomenalphysics3548]

Shut up

[@cyprianjude01]

Yippee