We actually tried a yoga ball! It didn't work very well. I think it's because the basketball needs to bounce on a hard surface to be able to compress and pass on its energy.
Physics Girl Hmm, that makes sense. So it's not just descending mass, but spring constant you have to be concerned about in the stacking. Physics and stuff!
NEW VIDEO! What happens when you drop a perfectly balanced stack of balls? And how is the result like a supernova? #physics ruclips.net/video/2UHS883_P60/видео.html
Βασιλική Βενιέρη Yeah, this is an interesting phenomena, I discovered this independently, using a basket ball and a super-ball. I was just telling one of my brothers about this effect, only a few weeks ago, although I did not know anyone else had noticed it. What I have discerned, is that the ball on top, strikes the ball beneath it, at twice the original speed. This is because the ball beneath it is rising at 1 speed unit, when the one above hits it with 1 speed unit, allowing an equivalent collision to dropping the top ball four times as far. Obviously you have to remove a little bit of speed, because the bottom ball slows down a little from the collision, so all in all, the top ball probably bounces somewhere just below 4 times as high as it fell. If this ball hits another ball above it (which would be the final ball at the top), well, you have one ball falling down at 1 speed unit, and another rising at 2 speed units, so the collision is 3 speed units. This obviously means it could rise to 9 times whatever distance it fell, if you neglect for friction, and the fact that the rising ball does not have infinite momentum, so it slows down a little. The fact that the rising ball is slowed down by the falling ball, means that some of the kinetic energy of the falling ball is lost (given to the ball beneath it), so it makes sense that the third ball rose to about 8 times it's original fall height. But theoretically, it actually can rise up to nine times as high. Of course, wind resistance becomes a large issue once the ball is in the air for any extended period of time.
It's so damn cool that we live in a time that people with a passion for physics or really any subject can create interesting videos to explain and share (and hopefully kindle) that passion with tens of thousands of others over the world in hours. I think if these trends continue, we might have an amazing amazing world several decades from now. I hope to see it. Sorry for an inane ramble, I just wanted to say thanks for being a cool person on the internet.
frollard What I was referring to is the current hypothesis that says universes come from the multiverse. So you'll have to start by creating the multiverse. If you subscribe to that theory.
Enjoyed the video but I (likely along with others) would prefer it if you added metric system units. No need to scrap the imperial but small footnotes would suffice.
Considered it, and I normally would. I thought this one was getting crowded with text so I decided not to. Good to know this was not the right decision. :)
Physics Girl If you consider this being an educational channel, just use the metric system and leave it at that. There's no point in artificially keeping alive the living dead :)
Sure it does. Doesn't change anything about our point, though ... P.S.: I only took a quick peek at later episodes, but my impression was she just did what I suggested (unknowingly of that change).
I hope that you get to show your own skills as a teacher someday. Turns out its harder than it looks. Like WAY harder. So much so, that RUclips is showing you the very very rarest of the best of the best. It's a big stretch to ask your music teacher to shred like Hendrix. If they can, you're VERY lucky.
So grateful for this video. I've tried a number of ways to describe and demonstrate this process for my students. This video was golden. Keep up the great work!
That was a fantastic demonstration of the transfer of momentum. Plus, it's easy enough to demonstrate in any school. Well done, Physics Girl, well done!
I played with this when I was younger! That's why I like your content so much. You make me feel that great feeling of discovering a new thing all over again. The enthusiasm in your videos is quite contagious, so cool.
( ͡° ͜c ͡° ) 1. She is an "aspiring physics major lady", and if I can English, that means she IS studying physics. 2. With the recent discovery of Higgs-Boson, the particle physicists probably have more job security for the next 10-15 years than any other job. Yes, you need to be that specialised to research on elementary particles. 3.Engineering cannot model a quantum vortex which is the main application of Vortex Physics. I think.
itsFisch Nah I just think fluid dynamics are awesome and mystifying and its difficult to find good demonstrations such as Physics Girl's. The rest is spot on though.
TheRebelSpyGamer Fluid vortex to quantum vortex... Well that escalated quickly. My bad i guess. From one physics major to another, I'm glad to hear you are enjoying your physics!
Really fantastic quality of videos on this channel, wonderful to see both great understandable explanations while maintaining fidelity to the laws of physics. Keep it up!
I want to run the smallest ball into space in this way. what I should do. and why I will not succeed. What is the maximum speed can be achieved and why that? what the barrier is?
Fun fact. In a supernova, much of the outward momentum that causes the explosion of the star is carried by neutrinos. But neutrinos almost never interact with atoms. If you fire a neutrino through lead, you need 1 light year of lead to have a 50% chance of an interaction with the lead. Yes, 1 light year... they don’t like interacting with other matter. So this gives you an idea of how many neutrinos are created during a supernova, but also it tells you just how dense the material in the star’s core is that many of the neutrinos actually do interact. The “wall” of collapsing stellar material is so incredibly dense that the neutrinos just can’t help hitting it and repelling it outwards.if you want to know more, I recommend the Crash Course Astronomy course with Phil Plait. It’s epic :)
A nice example of the role of mediation in collisions. In fact, it can be proven that in the limit of an increasing number of mediator particles of intermediary masses, the efficiency of the energy transfer will tend to 1, that is, all the energy will be transferred from the first (more massive) to the last (less massive) particle, as it happens in a Newton pendulum, where all masses are equal.
I'm more amazed they were able to stack those balls on top of each other and keep them stable. I was waiting for it to fall over while she was talking... PS they should team up with the slo-mo guys.
couldnt you try having 5 to 10 different balls stacked in a system of tubes, each tube being the size of each ball and once balls are dropped perfectly vertically the tubes are moved out of the way.
Great video. Could you do another one with a bit more info on the supernovas? I feel like you skimmed over that part. Also, is there a formula to determine height of the golf ball of you know the mass and regular bounce height of all the balls?
If you measure the difference in height of every ball involved, you can use this formula: (mass*(h2-h1)+[repeat for every ball except golf ball])/(mass_golfball)=heightincrease_golfball Heightincrease measured from the golf balls initial height
Blobfisher Very simply, the maximum height that can be achieved is equal to the original fall height times the amount of balls squared. Of course, if you include that the balls are not all falling from the same height, you can only get shorter distances than this. And if you want to include that the balls all fall a slightly different distance, just use the equating process: Golfball fall height + 1/2 The square root of Golfball fall height divided by Bouncy ball fall height + 1/2 The square root of Golfball fall height divided by basket ball fall height. This is if we account for the fact that they all fall a different distance, but still neglect friction. Now I think friction is what you really are concerned with when you talk about rebound coefficients. The fact is that the rebound coefficients are ALWAYS inconsistent. This is necessarily true. You cannot correctly apply the same rebound coefficients for a slow collision, as a fast collision. That would be (although you may not see why immediately) like saying wheels rolled with the same rolling friction coefficients, regardless of load. It would be completely useless to even try calculating how far the balls would go, if we wanted to include friction (especially inside the fabric of the balls), because the friction would never be equal to the amount of friction in an independent test, as when they are pressed under the load of other balls. It would be most convenient and efficient to say, that the top ball can rise to some height less than the drop height, multiplied by the amount of balls squared. It is not even necessary to include the mass or size of the balls in this equation, if you are trying to reach a convenient and useful answer. All balls will rise to the same height, if they are thrown upward at the same speed, and friction is neglected. So the only thing you need to calculate is the maximum speed of the top ball, which is simply it's original fall speed multiplied by the amount of balls used, because each ball adds one more multiple of this speed, as long as they all fall the same distance and friction is neglected. Of course the balls below the top one, will each add less than 1 speed unit to the above ball, because they do not have infinite mass or efficiency. The amount they will add, if only they're mass is a concern, is 1/2 of they're mass divided by the mass of the ball they strike, multiplied by they're original speed contribution to the collision. So if they have sufficiently large mass compared to the ball they strike, you can conclude they add they're collision speed to the speed of the ball they strike. They should all have the same collision speed if they fall the same distance and friction is neglected. Now if I have not said enough to explain how to properly calculate how high the top ball will reach, I don't know how or why, because I think this (as I call it, "Simplified") explanation runs through all the practical concerns.
+Jason Leo It is pretty obvious that those balls would need to be extremely well balanced and much much more massive than the ship. They would probably be way too imprecise for space travel. However... I think you may be on to something. This principle might have a use, if not in real life, at least in science fiction.
+androkguz yeah the balls would have to be tethered but my thinking is it doesnt even have to be balls maybe rubber cylinders or sets of plates with springs that are dropped together the springs compressing then releasing the pent energy. if it was built near dam water power could be used to lift the units over time before locking them in place ready for the drop whilst im unsure how far it could launch something it could save masses of fuel as they could punch the engines at the top of the jump
+Jason Leo the one problem with this idea is that the space ship and the crew inside would need to be extremely strong, because of the initial dropping momentum would slowly accelerate to an insane amount and then suddenly stop and then get multiplied tenfold in the opposite direction which would surely crunch any sort of spacecraft or the passengers. G-force in a nutshell.
***** u dont understand the spaceships destruction when its falling is not the problem, the problem is when all the energy 'bounces' back up to it, that amount of energy would be a ridiculous amount and would surely crush any object and if not crush then the passengers inside will completely get squashed inside against their seats or against walls.
+Jason Leo I immediately also was thinking how this could be used to get into orbit less expensively. Seems hard, and definitely not viable for human cargo. the g-force on the bonce have to be sick.
I watched this video because I've just seen the '3 balls drop' demonstrated on a BBC science documentary... but this video has made me understand it better. Thanks!
That was just amazing .., actually i got on to this site because i got a scientific lecture from Prof. Bhupati Chakravarti which i know that you are familier with him, he's from India. As Prof. Chakravarti taught me n my friends about the life of Science, i just got interest in it and i will surely come up with some positive response....Thanks for your tremendous Video that was very useful for me.
GREAT video! I used to teach college physics and I've used the plastic rings from empty rolls of cellophane tape to hold the balls in place, but rubber O-rings seem to be the best. The only problem with O-rings is finding them afterwards. Do NOT use metal washers unless you want to lose an eye, a tooth, or a window.
Love your videos, but could you please just use metric system? rest of the world use it, and I believe american can do both metric and imperial system.
If the vacuum chamber is on earth, where there is gravity, the balls would still lose energy from heating up the surface. This is caused by friction, which is present regardless of whether you're in a vacuum or not. But if you threw the balls in space, in a place where there's no gravity, the balls would keep going basically forever, because they don't have anything to touch to slow them down
Did that for a high school physics project (the balls, not the supernova!). Love it! Would be nice if the video also did the math to give the velocity of the top ball immediately after bound.
That bouncing effect of the multiple balls was sort of self-explanatory. But why, oh, why, use only weird units instead of at least also including the beautifully easy, worldwide-ly known and used metric ones?
The only measurement was height so I don't think it's a big deal. I'm sure physics girl knows metric quite well, it's hard getting past middle school without it.
Diana - this is even easier to explain if you say the basketball is bouncing back up at the tennis ball, so the relative speed is higher. then you have to do a reference frame shift: the floor isn't moving, but the basketball is - so you have to add this speed to the rebound of the tennis ball. the end result is the tennis ball is effectively bounding at 3 times the speed. Then you add the superball....
This is just excellent and should be shown in the schools. You are really good at this....I like your energy.... It just WORKS and you are fun to watch... The kids would remember watching.....
my 8yo daughter has just discovered your page and is hooked. fantastic vids and you evan manage to explain things so that i understand them. now if you could just explain the inverse square law then you would make my head stop hurting when my exams start lol.
"Stand back, I'm going to try some science." -awesome people everywhere! This was a great video, love the real-world practicality to explain something bordering on incomprehensible. -Shawn
Physics Girl King Crocoduck Huh, I kind of wonder if there is a mathematical rule behind how many balls stacked and how high the highest one will go. It would be kind of cool to see how many stacked balls would be needed to get the top one to say... the freedom tower or orbit.
Sarah Szabo The limit would probably be related to Hooke's law as much of the energy is transferred via the elastic nature of the basketball. Once you surpass the elastic limit the basketball will have lost its ability to rebound the other balls.
+Sarah Szabo , I have to say, that same thought occurred to me, about how to launch something into outer space. However, I figured the stress on the final object would be so great that it would be crushed or torn apart.
NickRoman I was just kind of thinking about it for fun. I think it would be wildly unrealistic to make any kind of space launch system off of this. Lol
While impulse energy transfer may be related to rigidity of the ball(s), the balls wouldbe limited in speed when the upward bouncing speed approaches the speed of 'sound' in the ball material.
I'm having a ball watching your super novel experiments! It would be neat if you could give an example of how what you are demonstrating in each video is used in daily life. Ex.; industry, applied science, etc..
I respect your opinion on the matter that god created the universe. In my opinion there is lack of evidence that god it. You should educate your fellow Christian brethren's, also tell tje ignorant ones to chill out and no one is persecuting them in the US.
Love the growing fanbase, love the unabated enthusiasm. In a Watch Later playlist that’s surpassed 200 videos (I really need to catch up!), I’m glad it’s yours that draws my attention first :)
I've watched a few videos now where you've talked about something bouncing, and you only ever mention energy lost to heat, but you don't mention sound. If you ask me, I'd say that explaining the loss of energy to sound is a lot easier for a person to grasp, since you can dribble a ball for a few minutes without noticing a change in temperature.
I know you mean that as a compliment but that's actually kind of insulting because it implies you value how she looks more than you value the information she is taking the time to share with you, and that she took the time to learn herself.
SepherStar lol, not neccessarily))) I think its obviously that I was joking ))) I understand that you are talking about good looking women struggle to be taken seriously, but if it is a small compliment like that, I don't think it will do much harm. Everybody loves compliments))
SepherStar I'm sick of this feminist bullshit. You can't just turn off the genes that make you attracted to a beautiful woman and make you lose concentrations. Parts of the male brain actually shut down in the presence of an attractive woman, and you call it disrespect? You're extremely ignorant and pretentious.
Boom Stick I'm a male feminist. I'm not 'turning off my genes'. But at the same time, she's not presenting a video inviting me to compliment her on her looks. She's presenting a video on classical mechanics. And she's doing a very good job at it. So yeah, cry me a fucking river about how feminism ruins your uninvited compliments. See if anyone cares.
Transformation of energy in its coolest form. Potential, kinetic, elastic and heat. Wicked! You demonstrated and explained this very clearly. I hope you can make people interested in physics and science. Subscribed! BTW do the neutrons in the supernova star 'bounce back' due to the Pauli Exclusion Principle? Or is it something else?
I wish there had been a warning included about double bouncing in this vid. People don't realize, but injuries where your foot literally unhinges from the ankle are a common occurrence (google it, warning graphic), such injuries normally happen several times a year at trampoline parks and are one of the reasons many pediatric groups recommend against backyard trampolines. The reason for these injuries is just like in the video, a larger kids momentum gets transferred to a smaller kid whose ankles can't support that amount of force, causing their feet to literally snap off.
I took an astronomy class and learned a lot about star formation and explosion, but they never quite explained that. I was always feeling kind of hazy about how the giant explosion happens. There's a "double bounce"! So, thanks!
I used this for a high school class I was guest teaching! My only advise: practice your aim so that you don't hit any students in the head (although it is a good way to keep their focus XD)
Right now on the news: A stack of 100 balls sent a satelite flying at .60c towards proxima centaury
LOOOOOOOOL
Best comment of all time.
Lol! :p
Haha and the tower was dropped to earth from the moon! 😂😂😂😂
I love this comment
If you could somehow balance that 4-stack on, say, a yoga ball, that top sucker would reach orbit
We actually tried a yoga ball! It didn't work very well. I think it's because the basketball needs to bounce on a hard surface to be able to compress and pass on its energy.
Physics Girl Hmm, that makes sense. So it's not just descending mass, but spring constant you have to be concerned about in the stacking. Physics and stuff!
Physics Girl What about...a bowling ball?
Timothy Milligan They do bounce a bit, so yeah that should be a nice little boost (and you could balance the basketball on one of the holes!)
Poor ground ...
NEW VIDEO! What happens when you drop a perfectly balanced stack of balls? And how is the result like a supernova? #physics ruclips.net/video/2UHS883_P60/видео.html
Ty for the info thats good stuff
I love the subjects that you choose to explain!They are so interesting!
Βασιλική Βενιέρη
Yeah, this is an interesting phenomena, I discovered this independently, using a basket ball and a super-ball. I was just telling one of my brothers about this effect, only a few weeks ago, although I did not know anyone else had noticed it. What I have discerned, is that the ball on top, strikes the ball beneath it, at twice the original speed. This is because the ball beneath it is rising at 1 speed unit, when the one above hits it with 1 speed unit, allowing an equivalent collision to dropping the top ball four times as far. Obviously you have to remove a little bit of speed, because the bottom ball slows down a little from the collision, so all in all, the top ball probably bounces somewhere just below 4 times as high as it fell. If this ball hits another ball above it (which would be the final ball at the top), well, you have one ball falling down at 1 speed unit, and another rising at 2 speed units, so the collision is 3 speed units. This obviously means it could rise to 9 times whatever distance it fell, if you neglect for friction, and the fact that the rising ball does not have infinite momentum, so it slows down a little. The fact that the rising ball is slowed down by the falling ball, means that some of the kinetic energy of the falling ball is lost (given to the ball beneath it), so it makes sense that the third ball rose to about 8 times it's original fall height. But theoretically, it actually can rise up to nine times as high. Of course, wind resistance becomes a large issue once the ball is in the air for any extended period of time.
Your videos are amazing, you are cool. Looking forward to your combined video with Vsauce,Veritasium and sixty symbols.
Why would you want people to not say this is interesting? This is science, a lot of us are scientists, these phenomena are exactly what interest us...
It's so damn cool that we live in a time that people with a passion for physics or really any subject can create interesting videos to explain and share (and hopefully kindle) that passion with tens of thousands of others over the world in hours. I think if these trends continue, we might have an amazing amazing world several decades from now. I hope to see it.
Sorry for an inane ramble, I just wanted to say thanks for being a cool person on the internet.
Great post Rockskillskids! Thank you.
Umm we already have an "amazing world" now. Been here the whole time friend.
I would try this at home but where am I going to get the dense part of a super nova? :p
To make an apple pie from scratch first you must invent the universe.
frollard So I take it you don't subscribe to the multiverse theory. :p
isgdre first you must invent *a* universe ;)
frollard What I was referring to is the current hypothesis that says universes come from the multiverse. So you'll have to start by creating the multiverse. If you subscribe to that theory.
isgdre What if one of the universes inside the multiverse had a multiverse inside it
What are these "feet" and "inches" you talk about early in the video? My physics books never mentioned any of those.
That's part of the customary system we use in America. If you live somewhere else, you use the metric system with meters.
He is making fun of it for being a very stupid system iam sure of (which it is honestly)
same....
Andreas Karlsson exactly, science should only use the International System's units
+Alexander Wittrup how tho?
Damn, your videos have gotten really good
Thank you!
Avec un public international ^^
Physics Girl yup in
+Physics Girl ur amazing
King Crocoduck oh, so they were not good before?
So refreshing To se you Diana! Praying for you to get well from Argentina.
Enjoyed the video but I (likely along with others) would prefer it if you added metric system units. No need to scrap the imperial but small footnotes would suffice.
Considered it, and I normally would. I thought this one was getting crowded with text so I decided not to. Good to know this was not the right decision. :)
Physics Girl
If you consider this being an educational channel, just use the metric system and leave it at that. There's no point in artificially keeping alive the living dead :)
I think the video gets the point across regardless of the measurement system used.
Sure it does. Doesn't change anything about our point, though ...
P.S.: I only took a quick peek at later episodes, but my impression was she just did what I suggested (unknowingly of that change).
Always use the SI units!
I figured this analogy out a long time ago between balls & supernova but had NEVER seen anyone else also use it. Thank you for proving I'm not crazy.
you should show my physics teacher how to teach a class properly...
or get a good looking chick to explain it?
mrjarjar1018 that helps
I hope that you get to show your own skills as a teacher someday. Turns out its harder than it looks. Like WAY harder. So much so, that RUclips is showing you the very very rarest of the best of the best. It's a big stretch to ask your music teacher to shred like Hendrix. If they can, you're VERY lucky.
@@mrjarjar1018 Yes, exactly - I think we've solved the mystery of how to get high school boys interested in physics...
Christian Nally
Another thing to note is that all the juicy stuff such as the equations are left out.
So grateful for this video. I've tried a number of ways to describe and demonstrate this process for my students. This video was golden. Keep up the great work!
That was a fantastic demonstration of the transfer of momentum. Plus, it's easy enough to demonstrate in any school. Well done, Physics Girl, well done!
Where has this channel been all my life
m.ruclips.net/channel/UC7DdEm33SyaTDtWYGO2CwdA
This is one of the most engaging Physics videos I've seen lately. Will be sharing your channel with students, friends and colleagues. Awesome job!
I played with this when I was younger! That's why I like your content so much. You make me feel that great feeling of discovering a new thing all over again. The enthusiasm in your videos is quite contagious, so cool.
I just found your channel when looking up vortex physics. As an aspiring physics major lady, I really enjoy your content! I hope to see much more
Why aren't you studying physics then? Also, why study physics? It's quite a dead end. Better study engineering.
( ͡° ͜c ͡° )
1. She is an "aspiring physics major lady", and if I can English, that means she IS studying physics.
2. With the recent discovery of Higgs-Boson, the particle physicists probably have more job security for the next 10-15 years than any other job. Yes, you need to be that specialised to research on elementary particles.
3.Engineering cannot model a quantum vortex which is the main application of Vortex Physics. I think.
itsFisch
Nah I just think fluid dynamics are awesome and mystifying and its difficult to find good demonstrations such as Physics Girl's. The rest is spot on though.
TheRebelSpyGamer
Fluid vortex to quantum vortex... Well that escalated quickly. My bad i guess. From one physics major to another, I'm glad to hear you are enjoying your physics!
Praying for you Dianna, hope you’re doing better. However dim it may be, there is a light at the end of the tunnel. Keep an eye on it.
Really fantastic quality of videos on this channel, wonderful to see both great understandable explanations while maintaining fidelity to the laws of physics. Keep it up!
Thank you!
I want to run the smallest ball into space in this way. what I should do. and why I will not succeed. What is the maximum speed can be achieved and why that? what the barrier is?
bounce to space
You're an excellent teacher. This really could help get a lot of people interested in science.
Why is no one asking how they managed to stack 3 balls?
hot glue
because everyone else paid attention to the video in which she addresses that and therefore no need to ask.
magic
Grow three, actually.
Afro King bro no if it was glue then how did they all bounce
Fun fact. In a supernova, much of the outward momentum that causes the explosion of the star is carried by neutrinos. But neutrinos almost never interact with atoms. If you fire a neutrino through lead, you need 1 light year of lead to have a 50% chance of an interaction with the lead. Yes, 1 light year... they don’t like interacting with other matter.
So this gives you an idea of how many neutrinos are created during a supernova, but also it tells you just how dense the material in the star’s core is that many of the neutrinos actually do interact. The “wall” of collapsing stellar material is so incredibly dense that the neutrinos just can’t help hitting it and repelling it outwards.if you want to know more, I recommend the Crash Course Astronomy course with Phil Plait. It’s epic :)
Was not expecting my first video from someone I've never seen before to be so damn educational. You earned a sub!
I have never seen a much better explanation of a supernova explosion... nice video !!!
You just keep getting better and better.
A nice example of the role of mediation in collisions. In fact, it can be proven that in the limit of an increasing number of mediator particles of intermediary masses, the efficiency of the energy transfer will tend to 1, that is, all the energy will be transferred from the first (more massive) to the last (less massive) particle, as it happens in a Newton pendulum, where all masses are equal.
Great tie in to super novae! I had never thought of it that way before.
I was searching for more ways to get hands-on activities into our astronomy class. What a neat idea. The kids will have so much fun with this! Thanks!
I'm more amazed they were able to stack those balls on top of each other and keep them stable. I was waiting for it to fall over while she was talking...
PS they should team up with the slo-mo guys.
This may be the clearest analogy to visualize what happens... Very nice!
couldnt you try having 5 to 10 different balls stacked in a system of tubes, each tube being the size of each ball and once balls are dropped perfectly vertically the tubes are moved out of the way.
This was awesome. This and the pool vortex videos are my favorite so far! So clear and concise. Very good visual representations.
Great video. Could you do another one with a bit more info on the supernovas? I feel like you skimmed over that part.
Also, is there a formula to determine height of the golf ball of you know the mass and regular bounce height of all the balls?
I think using p=m.v you can almost determine this ...
If you measure the difference in height of every ball involved, you can use this formula:
(mass*(h2-h1)+[repeat for every ball except golf ball])/(mass_golfball)=heightincrease_golfball
Heightincrease measured from the golf balls initial height
Blobfisher
Very simply, the maximum height that can be achieved is equal to the original fall height times the amount of balls squared. Of course, if you include that the balls are not all falling from the same height, you can only get shorter distances than this. And if you want to include that the balls all fall a slightly different distance, just use the equating process: Golfball fall height + 1/2 The square root of Golfball fall height divided by Bouncy ball fall height + 1/2 The square root of Golfball fall height divided by basket ball fall height. This is if we account for the fact that they all fall a different distance, but still neglect friction. Now I think friction is what you really are concerned with when you talk about rebound coefficients. The fact is that the rebound coefficients are ALWAYS inconsistent. This is necessarily true. You cannot correctly apply the same rebound coefficients for a slow collision, as a fast collision. That would be (although you may not see why immediately) like saying wheels rolled with the same rolling friction coefficients, regardless of load.
It would be completely useless to even try calculating how far the balls would go, if we wanted to include friction (especially inside the fabric of the balls), because the friction would never be equal to the amount of friction in an independent test, as when they are pressed under the load of other balls. It would be most convenient and efficient to say, that the top ball can rise to some height less than the drop height, multiplied by the amount of balls squared. It is not even necessary to include the mass or size of the balls in this equation, if you are trying to reach a convenient and useful answer. All balls will rise to the same height, if they are thrown upward at the same speed, and friction is neglected. So the only thing you need to calculate is the maximum speed of the top ball, which is simply it's original fall speed multiplied by the amount of balls used, because each ball adds one more multiple of this speed, as long as they all fall the same distance and friction is neglected. Of course the balls below the top one, will each add less than 1 speed unit to the above ball, because they do not have infinite mass or efficiency. The amount they will add, if only they're mass is a concern, is 1/2 of they're mass divided by the mass of the ball they strike, multiplied by they're original speed contribution to the collision. So if they have sufficiently large mass compared to the ball they strike, you can conclude they add they're collision speed to the speed of the ball they strike. They should all have the same collision speed if they fall the same distance and friction is neglected. Now if I have not said enough to explain how to properly calculate how high the top ball will reach, I don't know how or why, because I think this (as I call it, "Simplified") explanation runs through all the practical concerns.
so why not make 3 giant balls and put a spaceship at the top then drop the three making the rocket jump super high then alot less fuel will be needed
+Jason Leo It is pretty obvious that those balls would need to be extremely well balanced and much much more massive than the ship. They would probably be way too imprecise for space travel.
However...
I think you may be on to something. This principle might have a use, if not in real life, at least in science fiction.
+androkguz yeah the balls would have to be tethered but my thinking is it doesnt even have to be balls maybe rubber cylinders or sets of plates with springs that are dropped together the springs compressing then releasing the pent energy. if it was built near dam water power could be used to lift the units over time before locking them in place ready for the drop whilst im unsure how far it could launch something it could save masses of fuel as they could punch the engines at the top of the jump
+Jason Leo the one problem with this idea is that the space ship and the crew inside would need to be extremely strong, because of the initial dropping momentum would slowly accelerate to an insane amount and then suddenly stop and then get multiplied tenfold in the opposite direction which would surely crunch any sort of spacecraft or the passengers. G-force in a nutshell.
***** u dont understand the spaceships destruction when its falling is not the problem, the problem is when all the energy 'bounces' back up to it, that amount of energy would be a ridiculous amount and would surely crush any object and if not crush then the passengers inside will completely get squashed inside against their seats or against walls.
+Jason Leo I immediately also was thinking how this could be used to get into orbit less expensively. Seems hard, and definitely not viable for human cargo. the g-force on the bonce have to be sick.
I watched this video because I've just seen the '3 balls drop' demonstrated on a BBC science documentary... but this video has made me understand it better. Thanks!
That was just amazing .., actually i got on to this site because i got a scientific lecture from Prof. Bhupati Chakravarti which i know that you are familier with him, he's from India.
As Prof. Chakravarti taught me n my friends about the life of Science, i just got interest in it and i will surely come up with some positive response....Thanks for your tremendous Video that was very useful for me.
GREAT video! I used to teach college physics and I've used the plastic rings from empty rolls of cellophane tape to hold the balls in place, but rubber O-rings seem to be the best. The only problem with O-rings is finding them afterwards. Do NOT use metal washers unless you want to lose an eye, a tooth, or a window.
Love your videos, but could you please just use metric system? rest of the world use it, and I believe american can do both metric and imperial system.
Irun Mon Its a little late to change it now mate
This was great! Can't wait to try that. Thanks for including the kids on the trampoline. They were so happy to be a part of it. Miss you!
PLEASE GET THE 4 STACK BALL TO WORK
I like this video a lot. Great work, Dianna!!!
would the balls dropped still lose energy due to sound if dropped in a vacuum?
I don't think they would, at least not to sound, since if it's a perfect vacuum there is no medium for the vibrations to travel through.
+miner69erher
I think they would since there must be a surface for the ball to bounce off.
If the vacuum chamber is on earth, where there is gravity, the balls would still lose energy from heating up the surface. This is caused by friction, which is present regardless of whether you're in a vacuum or not. But if you threw the balls in space, in a place where there's no gravity, the balls would keep going basically forever, because they don't have anything to touch to slow them down
How could you inflate balls in a vacuum. Maybe you just put a small amount of air in them and they are inflated.
There would still be some sound tranferred through to the surface they bounce off.
Did that for a high school physics project (the balls, not the supernova!). Love it! Would be nice if the video also did the math to give the velocity of the top ball immediately after bound.
why do i want to listen to everything she says... like.... i want to go running with her.
***** I watch videos and leave comments was is there not to understand?
and give birth to the modern isaac newton
+Pikapetey Coz ur a loser
+datstocklyfe Seriously she should
+Pikapetey
Would you like some water? You seem quite thirsty.
I wanna be thanked too for jumping on a trampoline 3:17
That bouncing effect of the multiple balls was sort of self-explanatory. But why, oh, why, use only weird units instead of at least also including the beautifully easy, worldwide-ly known and used metric ones?
'Merica
Jason Is Awesome! *'Murica.
America
'Murica Fuck Yeah!
The only measurement was height so I don't think it's a big deal. I'm sure physics girl knows metric quite well, it's hard getting past middle school without it.
Now, that's a great video. Excellently produced and explained. Big Bang, expanding universe theory; so many applications. Very nice.
I wonder how many balls would it take to launch the ball at escape velocity...
I majored in physics but never thought about this. It's a great experiment and I love what you're doing. :)
She knows alot about balls
That sound wrong. No offence.
+Ella Meese that's the idea
im offended
HAHA loled
HaxaAccet this comment has 69 likes
Diana - this is even easier to explain if you say the basketball is bouncing back up at the tennis ball, so the relative speed is higher. then you have to do a reference frame shift: the floor isn't moving, but the basketball is - so you have to add this speed to the rebound of the tennis ball. the end result is the tennis ball is effectively bounding at 3 times the speed. Then you add the superball....
Incredible
I like your hat.
Okay, I did NOT see the transition from ball bounce to supernova coming. Bravo!
thanks for keeping this in: 1:51
made me giggle..
this is literally the best visual explanation of how a supernova works.
You lost me when you started to count your distances in bodyparts.
Just found out this channel, pretty sweet, It shows some basic fundamentals of physics, but in a way I never thought of it
Please, if you agree with science, use the metric system! Or in either case, use both systems.
This was pretty darn cool. Great video, Dianna.
Agreed
She's pretty and smart, A dangerous combination. great video.
This is just excellent and should be shown in the schools. You are really good at this....I like your energy.... It just WORKS and you are fun to watch... The kids would remember watching.....
Wait, you have a science channel but you give mesurements in imperial units? What the fuck? :D
JuglarEuskaldun because it's science for dummies!
Hahaha jk
my 8yo daughter has just discovered your page and is hooked. fantastic vids and you evan manage to explain things so that i understand them. now if you could just explain the inverse square law then you would make my head stop hurting when my exams start lol.
Thanks to "e-penser" for bring me here :D
(French science channel) ;)
Azuma :o
I'm preparing for a physics contest and this is actually soooo helpful for me to understand the exam problems! This video is awesome!!! Thanks a lot!!
Is this even legal?
no, you are under arrest for trying it
Nikole Powell for public disorder
"Stand back, I'm going to try some science." -awesome people everywhere!
This was a great video, love the real-world practicality to explain something bordering on incomprehensible.
-Shawn
2:09
I love so much your eyes
MK73DS grow up.
wtf! jesus christ, someone was desperate a year ago!!! gosh XD
Jesus Christ can help someone with desperation.
lol
MK73D
I can't believe you explained to me so easily why supernova explode.
My mind is blown and I'm a physicist.
Physics Girl King Crocoduck Huh, I kind of wonder if there is a mathematical rule behind how many balls stacked and how high the highest one will go. It would be kind of cool to see how many stacked balls would be needed to get the top one to say... the freedom tower or orbit.
Sarah Szabo The limit would probably be related to Hooke's law as much of the energy is transferred via the elastic nature of the basketball. Once you surpass the elastic limit the basketball will have lost its ability to rebound the other balls.
+Sarah Szabo , I have to say, that same thought occurred to me, about how to launch something into outer space. However, I figured the stress on the final object would be so great that it would be crushed or torn apart.
NickRoman
I was just kind of thinking about it for fun. I think it would be wildly unrealistic to make any kind of space launch system off of this. Lol
While impulse energy transfer may be related to rigidity of the ball(s), the balls wouldbe limited in speed when the upward bouncing speed approaches the speed of 'sound' in the ball material.
I'm having a ball watching your super novel experiments!
It would be neat if you could give an example of how what you are demonstrating in each video is used in daily life. Ex.; industry, applied science, etc..
Sweet
I would just like to tell you that I absolutely love your videos! I use them all the time in my classroom!!!
Most viewers: "wow! Now how do i get her to be with me?" Me: how the hell do you balance a ball on a ball on a ball? Atleast i got my answer
Youre videos keep getting better! this was so interesting!
christians would argue jesus worked in mysterious ways
+Will Lowe How else would you explain what happened?
I respect your opinion on the matter that god created the universe. In my opinion there is lack of evidence that god it. You should educate your fellow Christian brethren's, also tell tje ignorant ones to chill out and no one is persecuting them in the US.
Love the growing fanbase, love the unabated enthusiasm. In a Watch Later playlist that’s surpassed 200 videos (I really need to catch up!), I’m glad it’s yours that draws my attention first :)
Physics girl, I am in love with you... Our love is so quantum, it only exists in another place and time........
I've watched a few videos now where you've talked about something bouncing, and you only ever mention energy lost to heat, but you don't mention sound. If you ask me, I'd say that explaining the loss of energy to sound is a lot easier for a person to grasp, since you can dribble a ball for a few minutes without noticing a change in temperature.
so pretty. i mean interesting
oooh 27 likes and two comments. This is a personal record
Why gotta leave the lame and creepy compliment comment for? Can't you just watch a pretty girl without bringing up looks?
gay ^
jordanstead When you get a girlfriend you'll understand
still gay ^
Your videos keep getting cooler every time!
I like a girl who knows a thing or two bout balls
i love the word physicsing. awesome . i lov ur Chanel
what are those
This is very cool. I did not know that the momentum of the larger ball would transfer energy into the upper balls.
she is so cute
This is the best demonstration I've seen!
If you were my physics teacher, I would find it really hard to concentrate on subject :)
I know you mean that as a compliment but that's actually kind of insulting because it implies you value how she looks more than you value the information she is taking the time to share with you, and that she took the time to learn herself.
SepherStar lol, not neccessarily))) I think its obviously that I was joking ))) I understand that you are talking about good looking women struggle to be taken seriously, but if it is a small compliment like that, I don't think it will do much harm. Everybody loves compliments))
SepherStar
Isn't this a strange bizarro world, where complimenting someone for being beautiful is an insult...
SepherStar I'm sick of this feminist bullshit. You can't just turn off the genes that make you attracted to a beautiful woman and make you lose concentrations. Parts of the male brain actually shut down in the presence of an attractive woman, and you call it disrespect? You're extremely ignorant and pretentious.
Boom Stick I'm a male feminist. I'm not 'turning off my genes'. But at the same time, she's not presenting a video inviting me to compliment her on her looks. She's presenting a video on classical mechanics. And she's doing a very good job at it.
So yeah, cry me a fucking river about how feminism ruins your uninvited compliments. See if anyone cares.
You must be having so much fun making these videos. Thanks for your effort, it is much appreciated.
Transformation of energy in its coolest form. Potential, kinetic, elastic and heat. Wicked!
You demonstrated and explained this very clearly. I hope you can make people interested in physics and science. Subscribed!
BTW do the neutrons in the supernova star 'bounce back' due to the Pauli Exclusion Principle? Or is it something else?
I wish there had been a warning included about double bouncing in this vid. People don't realize, but injuries where your foot literally unhinges from the ankle are a common occurrence (google it, warning graphic), such injuries normally happen several times a year at trampoline parks and are one of the reasons many pediatric groups recommend against backyard trampolines. The reason for these injuries is just like in the video, a larger kids momentum gets transferred to a smaller kid whose ankles can't support that amount of force, causing their feet to literally snap off.
That's a really neat demonstration, thanks. Oddly it reminds me of the way a detonation shock wave propagates through a high explosive.
I took an astronomy class and learned a lot about star formation and explosion, but they never quite explained that. I was always feeling kind of hazy about how the giant explosion happens. There's a "double bounce"! So, thanks!
I used this for a high school class I was guest teaching! My only advise: practice your aim so that you don't hit any students in the head (although it is a good way to keep their focus XD)
Kudos for pointing out the link to supernovae.
Fantastic demos for Science popularization most of which which I also use in my demo.
of the best physics "tricks" ever. Love this one.
My dad's a physicist. I know most of this stuff. IT'S AWESOME!!!
Very nice, and more instructive than a lesson of science in french school ! ;)
You can do this inside a 5 Below. They have all the different balls shown (although they somewhat vary on the golf ball.)