Newton's Remarkable Cradle

[@EugeneKhutoryansky]

I am glad that you showed what happens when you raise three or four balls, or one ball on one side and two balls on the other. When we were approaching the end of the video, and this hadn't yet been shown, I was afraid that this was going to be left out.

[@kingkirby8960]

HEY, I LOVE YOUR VIDS!

[@manasansiva8878]

What if the last two balls were glued together, this will cause them to act as one ball but this also doesn't seem to obey the conservation of kinetic energy?

[@DavidG2P]

Oops, that's embarrassing that you didn't notice that this video is completely wrong

[@ConstantineLyhnaropoulos]

Once again your video is spectacular!!

[@modestyisgood4933]

I love your videos! keep up posting cool material.

[@Tralbi8]

your videos make me love physics more than anything else. keep up with your posts on the channel :)

[@mazdysoraya6121]

Thank you sir, i really love science. Your content and explanation are so good. And your voice is perfect sir.

[@RandyHencke]

Thanks! a very satisfying explanation of why the two ball case results are the observed results.

[@andyveh221]

The conservation laws for momentum and energy are not enough. Take a typical elastic carts demonstration and you can see that the incoming cart (if less massive) rebounds to the right. That is obviously not what Newton's cradle is doing but it is a theoretical possibility based on the two conservation laws. In the case shown (right_one incoming ball), these are possible solutions: right_one stops at 0 v and left_one swings left at -1 v (that's what we see), but also 1 w/ 0.33 v and 2 w/ -0.67 v, 1 w/ 0.5 v and 3 w/ -0.5 v, 1 w/ 0.6 v and 4 w/ -0.4 v. Search for Newton's cradle, "Gavenda", "Simanek", "Hutzler", all of which show that there's more than p and KE to it.

[@halitozgur6166]

This was beautiful.

[@manasansiva8878]

What if the last two balls were glued together, this will cause them to act as one ball but this also doesn't seem to obey the conservation of kinetic energy?

[@dadsan7331]

I have exactly the same question...

[@majidijaz8974]

if we add two little balls in the place of last ball .The two ball have same mass as the last big ball then what happen ?

[@lakshmivengat8614]

excellent explanation......

[@ddburdette]

What I'k like to know and which I could not find an answer to online is what happens if the balls in the cradle are not equal in mass?

[@ryanchowdhary965]

nothing special, just the one with greater mass will have lesser displacement than the others.

[@banelemahlangu8619]

Great explanation honestly I don't understand why the are some folks whom disliked the video

[@MetricZero]

I love your videos. Thanks!

[@PacoOtis]

Thanks for the video!! Well done!

[@hopudesu9655]

may u please describe what happens in terms of forces and how they caused the motion -a reply would be greatly appreciated

[@subhashsingh-zq6ou]

Really great video sir:-)

[@emailyarabrandao]

hi there. i know this video is a bit old but i just now got one of these. i have loved this toy since i was a kid. i have a question though, do the balls keep on going forever? it seem like mine stops very soon, i hardly get the time to enjoy wathing them. not even 40 seconds playing. thanks.

[@TomKappeln]

Hi Yara. How long they bounce depends MOSTLY of the hardness of the balls (Like in real life) lol Most of the cradles out there are realy cheap and have bad balls .... (Also like in real life) So no wonder you hardly could enjoy them .... (You know it)

[@majidijaz8974]

i have a question!

[@rogerscottcathey]

was waiting to see a lateral swing of one.

[@421sap]

Thank you.

[@askmuhsin]

As usual very informative video... What if the displaced sphere has a mass of 2m, while the other 4 sphere has a mass of m...

[@arjunarun9147]

The ball at the end is displaced a greater distance with higher velocity

[@thecal_and_dillyshow]

Wow! I want one 😂

[@mereesmariajose5361]

👌🏻👌🏻

[@FindLiberty]

Next, try the free-falling, "small ball riding on top of a much larger ball when dropped together" experiment. Bouncy rubber balls, hard plastic or metal bearings perform anywhere from great to downright scary (the latter requires safety glasses). Try a triple stack of progressive sizes. Could a top ball ever reach low space orbit, or would it just explode on lift-off? lol

[@misclickable]

Physics Girl has a video about that. It was entertaining and informative. I suggest you check it out!

[@FindLiberty]

+jmovlogs Good catch! Poor choice of words on my part (orbit). I know it is not possible, but if you try it using baseball size steel bearings, and don't put an eye out in the process, you will see why I took a shot at that high altitude reference. It can be quite violent; glass marbles will explode; steel ones might punch a hole into the drywall ceiling if attempted indoors. Shatterproof safety glasses! Must launch off of massive hard surface, like an anvil. I seem to recall the distinctive sound of the small bearings ZZZzzzzinging by. It could be quite dangerous!

[@davirasuciati8722]

Hello, I'm Davira. I hope you can reply to this comment I think this video is amazing I want to ask permission to use this video for my undergraduate thesis I made a book with additional videos that can be accessed through an application, this video will be included in my application that I made I will still include your channel thanks for your attention

[@ryanchowdhary965]

the guy died years ago...

[@The_A_Cast]

Absolutely love these videos! But, one thing I didn’t find special, in my opinion, was their formula of 1/2mv squared = 1/2mv squared. If you take half of anything multiplied together and square it, it will obviously be the same of what you multiplied before halving it and squaring it. 🤷🏼‍♂️

[@multanisaab7412]

Nice

[@achild5864]

this hurts my brain

[@TomKappeln]

Completely WRONG ! Make a slow motion video of dropping TWO balls, and you will see WHY ! You make the mistake counting the TWO dropping balls as ONE MASS ! Think of it ! In slow motion you can CLEARLY see that dropping TWO balls leads to TWO separate impacts ! THIS is why TWO dropping balls provides to the TWO "escaping" balls and NOT Newtons 3 law !

[@DavidG2P]

👆 this. You nailed it, and this video's explanation is bullshit.

[@JUNGELMAN2012]

This does not explain anything. The spheres don't know math or formula's. You just proved that the math holds only in one solution. The better explanation might be found considering multiple spheres as delayed multiple collisions.

[@DavidG2P]

This explanation is total bullshit, and I found out that it is, as a kid, by playing with my Newton's cradle for a year or so.

[@TomKappeln]

Thank you for your kind comment on my explantation.

[@DavidG2P]

It's the number of collisions that determines the number of balls flying off at the other end, not some system of energy and momentum equations

[@manasansiva8878]

What if the last two balls were glued together, this will cause them to act as one ball but this also doesn't seem to obey the conservation of kinetic energy?

[@askmuhsin]

As usual very informative video... What if the displaced sphere has a mass of 2m, while the other 4 sphere has a mass of m...

[@askmuhsin]

As usual very informative video... What if the displaced sphere has a mass of 2m, while the other 4 sphere has a mass of m..

[@LukeSumIpsePatremTe]

On both sides mass of 2 _m_ would move at the speed of _v_. So on the other side one ball with mass of 2 _m_ would move at the speed of _v_. And on the other side 2 balls with mass of 2 _m_ would move at the speed of _v_. That way kinetic energy and momentum would both conserve.