A Physics Question

Message Bookmarked

Bookmark Removed

http://images.google.co.uk/images?q=tbn:W71sHWNm_IwJ:http://thumb4.shutterstock.com

Mr R and I were discussing whether a bouncy ball, if dropped from a height of say 30,000ft would bounce or create a hole in the ground.

― Rumpie, Friday, 11 November 2005 09:46 (twenty years ago)

We didn't come to any conclusion. I insisted that it would bounce, he said it would make a lil crater.

― Rumpie, Friday, 11 November 2005 09:47 (twenty years ago)

id say bounce

It would only be able to reach a certain velocity - its terminal velocity anyway. So, beyond a certain height, increasing the height wont make it go any faster. Havent done physics in awhile though.

― splates (splates), Friday, 11 November 2005 09:49 (twenty years ago)

Yeah, a bouncy ball isn't particularly heavy. I think it would bounce like a mo-fo.

― Rumpie, Friday, 11 November 2005 09:53 (twenty years ago)

i think it would most likely break. the limits of its bounciness having been reached when it hits the ground at its terminal velocity

― Britain's Obtusest Shepherd (Alan), Friday, 11 November 2005 10:15 (twenty years ago)

http://images.google.co.uk/images?q=tbn:2xzCNRIB2MoJ:http://jessaroo.12hours.us/Images

― Rumpie, Friday, 11 November 2005 10:15 (twenty years ago)

What, like into wee bits?

― Rumpie, Friday, 11 November 2005 10:16 (twenty years ago)

i think it would most likely break

i agree.

― not-goodwin (not-goodwin), Friday, 11 November 2005 10:18 (twenty years ago)

Also, the rubber of the bouncey ball (assuming that it's rubber, but even if it was plastic, same problem) would be so weakened by the cold at such high altitudes, and the heat generated by the friction of falling so far so fast, that it would probably disintergrate before it even hit the ground.

― Stress Pig (kate), Friday, 11 November 2005 10:20 (twenty years ago)

i feel like i should link to that telly ad i blogged with the thousands of bouncy balls and the Jose Gonzales cover of heartbeats - is pretty

― Britain's Obtusest Shepherd (Alan), Friday, 11 November 2005 10:24 (twenty years ago)

Ok, yeah it would probably disintegrate, but just assuming it was resistant to the heat from air resistance, and it reaches the ground, would it bounce or make a crater? I still say bounce.

― splates (splates), Friday, 11 November 2005 10:27 (twenty years ago)

bounce.

― g-kit (g-kit), Friday, 11 November 2005 10:29 (twenty years ago)

it would still break if you assume temperature isn't extreme.

if you assume the intramolecular bonding is enough to maintain shape then it would bounce.

― Britain's Obtusest Shepherd (Alan), Friday, 11 November 2005 10:31 (twenty years ago)

It was that ad which prompted the discussion Alan.

Also the programme about the chap who collected elastic bands and made a huge ball. His ambition was to bounce it from a height. He had a crane hoist it maybe 50, 60ft into the air, when he dropped it, it went thud.

― Rumpie, Friday, 11 November 2005 10:40 (twenty years ago)

What's even cooler, is if the ball had an infinite mass, it would be like a black hole and suck everything in when it bounced.

― MESTEMA (davidcorp), Friday, 11 November 2005 10:48 (twenty years ago)

I'd say it would bounce, but leaving some sort of indentation behind it.

― NickB (NickB), Friday, 11 November 2005 10:52 (twenty years ago)

I'm not sure the ball in question has a critical mass.....

http://images.google.co.uk/images?q=tbn:Dgyzwclp6FcJ:http://photos23.flickr.com/28836440

― Rumpie, Friday, 11 November 2005 10:53 (twenty years ago)

That's very diplomatic Nick...

― Rumpie, Friday, 11 November 2005 10:54 (twenty years ago)

ok then http://www.fallon.co.uk/ click Work>Sony Bravia

― Britain's Obtusest Shepherd (Alan), Friday, 11 November 2005 10:55 (twenty years ago)

Google Image Search has a different idea of a bouncy ball

http://images.google.co.uk/images?q=tbn:vVcBQx0FfhkJ:www.verymerryseamstress.com

― Rumpie, Friday, 11 November 2005 11:13 (twenty years ago)

what if a monkey hit the ball with a tennis racket?

― g-kit (g-kit), Friday, 11 November 2005 11:17 (twenty years ago)

xpost

i don't think that would bounce to well.

what if a monkey hit the ball with a tennis racket?
what on earth made you think of that g-kit?

― not-goodwin (not-goodwin), Friday, 11 November 2005 11:20 (twenty years ago)

it would probably bounce a little. i doubt a bouncey ball would reach some crazy ass terminal velocity so high that it'd actually break into pieces. probably the same velocity as you'd get dropping it from 5 stories high.

but - it wouldn't bounce a lot, it'd bounce a bit because it would warp a bit i bet. so it'd bounce a bit like a slightly deflated football.

depends on the ball!

― ken c (ken c), Friday, 11 November 2005 11:24 (twenty years ago)

That ad is fucking tremendous. Genius.

― Rumpie, Friday, 11 November 2005 11:26 (twenty years ago)

What about the gurning badly dressed ball Google threw up?

― Rumpie, Friday, 11 November 2005 11:27 (twenty years ago)

A Chemistry Question:

If you drop a big big lump of mercury from top of a building onto the top of a hilly road. would it all shatter and bounce down the road like that advert? and would everyone on that street then be killed by mercury poisoning?

and at the bottom of the road, will the mercury all merge back together into T-1000?

― ken c (ken c), Friday, 11 November 2005 11:51 (twenty years ago)

Freddie Mercury?

― Rumpie, Friday, 11 November 2005 11:57 (twenty years ago)

It would bounce. It's a bouncy ball. What's wrong with you people?

― Teh HoBB at work, Friday, 11 November 2005 12:14 (twenty years ago)

it wouldn't bounce in water!

― ken c (ken c), Friday, 11 November 2005 12:16 (twenty years ago)

It wouldn't land in water, it's a bouncy ball. Bouncy balls are repelled by water and attracted to trampolines.

― Teh HoBB at work, Friday, 11 November 2005 12:21 (twenty years ago)

I once threw a bouncing ball in the shop. It bounced all over the place and then hit a client. The woman was extremely angry saying I shouldn't be doing that. So I threw the ball again. It bounced all over the place... and hit the woman on the legs again. She claimed I did this on purpose. ROFL. What are the chances of that. I had a good laugh afterwards though.

― Nathalie, the Queen of Frock 'n' Fall (stevie nixed), Friday, 11 November 2005 12:22 (twenty years ago)

surely you mean BOFL! :-D

― ken c (ken c), Friday, 11 November 2005 12:23 (twenty years ago)

The terminal velocity of a ball wouldn't be terribly high - I'd guess it would be reached in dropping it from a skyscraper, let alone a plane. Some are stronger than others, so there's no answer as to whether it would break, and we haven't established what it lands on - solid steel, it doesn't leave a mark, loosely packed Earth, it makes a big dent. This also settles whether it bounces, how much energy is used in making the dent (as well as heat and sound), and how much is bounced back into the ball.

I've not seen that ad, Ken. I can't think what a 'lump of mercury' might be.

― Martin Skidmore (Martin Skidmore), Friday, 11 November 2005 12:33 (twenty years ago)

A concrete pavement?

― Rumpie, Friday, 11 November 2005 12:52 (twenty years ago)

a lump. like if you have it in a huge bag and just lob it.

― ken c (ken c), Friday, 11 November 2005 13:32 (twenty years ago)

I am SO going to be unable to walk down the street today for fear of bouncy balls, lumps of mercury, Freddie Mercury and babies falling on my head. Thanks, all.

― Big Loud Mountain Ape (Big Loud Mountain Ape), Friday, 11 November 2005 13:47 (twenty years ago)

Not to mention pennies falling from Empire State Buildings.

― Rumpie, Friday, 11 November 2005 14:10 (twenty years ago)

A penny falling from the Empire State Building would leave a crater half a mile wide. That's why they have the railings

― robster (robster), Friday, 11 November 2005 14:24 (twenty years ago)

More physics questions, please. I have no idea who's making shit up but this is fascinating.

― mcd (mcd), Friday, 11 November 2005 14:48 (twenty years ago)

a crater half a mile wide

it would if the penny was half a mile wide.

― not-goodwin (not-goodwin), Friday, 11 November 2005 14:59 (twenty years ago)

Why is a mouse when it spins?

― Britain's Obtusest Shepherd (Alan), Friday, 11 November 2005 15:00 (twenty years ago)

Okay, sent this to Any Question Answered - "What would happen if you dropped a standard bouncy ball onto concrete from 30,000ft?"

Druming my fingers, awaiting the answer.

― Rumpie, Friday, 11 November 2005 15:50 (twenty years ago)

AQA: 'A bouncy ball dropped from that height would still bounce up again. AQA predicts that it would bounce rather high on the rebound from the drop.'

― Rumpie, Friday, 11 November 2005 15:55 (twenty years ago)

hahaha i love how they refer to themselves in third person.

― ken c (ken c), Friday, 11 November 2005 15:57 (twenty years ago)

I think they're wrong. Contest that.

― Stress Pig (kate), Friday, 11 November 2005 15:58 (twenty years ago)

V = sqrt[(2*m*g)/(Cd*rho*A)]

where:

m = mass of object
g = acceleration due to gravity
Cd = coefficient of drag
rho = density of air
A = frontal area of the object
V = airspeed of the object

― o. nate (onate), Friday, 11 November 2005 15:58 (twenty years ago)

blimey! x-post or what...

has anyone worked out/looked up what the terminal velocity would be?

― Britain's Obtusest Shepherd (Alan), Friday, 11 November 2005 15:59 (twenty years ago)

"There is no possible way that this could happen as ball would disintegrate into dust from the extreme pressure (from heat though, rather than cold) but if it did it would depend on the laws of elasticity. It would probably bounce, but it could never happen. So the answer as to making a hole or bouncing is an unknown." answer from Physics Phd student aka boyfriend.

― jocelyn (Jocelyn), Friday, 11 November 2005 15:59 (twenty years ago)

I mean, that's up in the Troposphere, isn't it? (resists obvious puns)

http://liftoff.msfc.nasa.gov/academy/space/atmos.gif

x-post

― Stress Pig (kate), Friday, 11 November 2005 16:00 (twenty years ago)

Pressure may not be the right word, I'm paraphrasing.

― jocelyn (Jocelyn), Friday, 11 November 2005 16:00 (twenty years ago)

30000 feet = 9.144 kilometers yes which puts it in the troposphere. Very cold up there! Rubber would freeze and crack.

― Stress Pig (kate), Friday, 11 November 2005 16:01 (twenty years ago)

(And the Byrds were wrong - Eight Miles High is not actually in the Stratosphere yet.)

― Stress Pig (kate), Friday, 11 November 2005 16:02 (twenty years ago)

Well, the poster didn't specify that the bouncy ball is made of rubber. Perhaps it's some sort of cold-resistant plastic compound.

― o. nate (onate), Friday, 11 November 2005 16:11 (twenty years ago)

However, I think that Jocelyn's PhD boyfriend is probably correct that the problem will be heat not cold. Since the ball is dropped so high, where the air is very then, the terminal velocity will be extremely high, and when the ball reaches the atmosphere, it will burn up.

― o. nate (onate), Friday, 11 November 2005 16:13 (twenty years ago)

"then" = "thin"

― o. nate (onate), Friday, 11 November 2005 16:13 (twenty years ago)

Oh wait, sorry, 30,000 ft isn't all that high. Never mind.

― o. nate (onate), Friday, 11 November 2005 16:15 (twenty years ago)

I think dropping it from 100,000+ feet would allow it to reach a higher terminal velocity in the upper atmosphere. It would hit considerably faster than its 60,000 foot terminal velocity.

― Jdubz (ex machina), Friday, 11 November 2005 16:20 (twenty years ago)

This thread is awesome and that sony ad plus that picture of the little spaceshuttle in the thermosphere rocks my morning. I really hope the answer is either "yes, it bounces" or "it creates mass destruction, buy canned goods, bottled water, run for lives."

― rrrobyn (rrrobyn), Friday, 11 November 2005 16:20 (twenty years ago)

NASA always has the greatest infographics.

― Stress Pig (kate), Friday, 11 November 2005 16:21 (twenty years ago)

The temperature at 30,000 ft is -49 F. Pretty cold. I wonder if there is any bouncy plastic compound that could withstand that.

― o. nate (onate), Friday, 11 November 2005 16:22 (twenty years ago)

Silicone rubber can withstand temperatures as low as -75 F. Don't know how well it bounces though.

― o. nate (onate), Friday, 11 November 2005 16:28 (twenty years ago)

These might work:

http://www.firetoys.co.uk/juggling/Pure_silicone_bounce_ball.html

― o. nate (onate), Friday, 11 November 2005 16:29 (twenty years ago)

Weren't the Space Shuttle's O-Rings made out of silicone? They still cracked and disintergrated. On the way up, even not on the way down, which is more stressful to materials.

― Stress Pig (kate), Friday, 11 November 2005 16:30 (twenty years ago)

Well, the shuttle went considerably higher than 30,000 ft, where temperatures are even lower. And presumably they found an improved material to use for those O-Rings, perhaps another form of silicone?

― o. nate (onate), Friday, 11 November 2005 16:37 (twenty years ago)

Whether it leaves a crater or bounces or does both has more to do with the resiliency of the ball and the surface it impacts.

High speed photo sequence of a racquet ball hitting a wall at 60 mph. (this is a pdf file).

The more deformation the ball takes at impact, the less deformation there will be of the contacting surface.

― Jaq (Jaq), Friday, 11 November 2005 16:41 (twenty years ago)

And it was actually the heat from the exhaust gasses that caused the o-rings to fail on the shuttle, not cold.

― Jaq (Jaq), Friday, 11 November 2005 16:43 (twenty years ago)

Okay, if we ignore air resistance then all the potential energy that the ball has before it is dropped will be transferred into kinetic energy right before it hits. If PE = mgh, where mass m is approx 200g, acceleration due to gravity g is 9.8 ms^2 and height h = 9144 metres, then the total KE of the ball right before impact will be approx 17.9 kJ. If all this kinetic energy is transferred into heat on collision, then I calculate that the final furious impact will have the same devastating consequences as would be unleashed by setting fire to a (standard size) Snickers bar.

― NickB (NickB), Friday, 11 November 2005 16:44 (twenty years ago)

Well, the shuttle went considerably higher than 30,000 ft, where temperatures are even lower.

http://www.aerospaceweb.org/question/spacecraft/q0183.shtml

― Jdubz (ex machina), Friday, 11 November 2005 16:45 (twenty years ago)

That looks like one of those bouncy popper things we had a craze for at school in about 1985. (x-post)

― Mädchen (Madchen), Friday, 11 November 2005 16:47 (twenty years ago)

for a moment there i was certain that there was a layer of atmosphere called the menopause

― ken c (ken c), Friday, 11 November 2005 16:47 (twenty years ago)

― Jdubz (ex machina), Friday, 11 November 2005 16:52 (twenty years ago)

These might work:
http://www.firetoys.co.uk/juggling/Pure_silicone_bounce_ball.html

and these balls ARE amazing and they do bounce. better than your standard balls.

― ken c (ken c), Friday, 11 November 2005 16:52 (twenty years ago)

have you tried burning a whole snickers bar. that's a lot of sugar.
heat capacity of rubber is on the order of 2000 /JKgK and at 200g that's 400J will raise by 1K = the temperature of the ball will go up on the order of 50 degrees. ish

― Britain's Obtusest Shepherd (Alan), Friday, 11 November 2005 16:52 (twenty years ago)

So it'll bounce fine but get a little warm, right?

― Markelby (Mark C), Friday, 11 November 2005 16:56 (twenty years ago)

It may not bounce at all, but simply melt and spread a thin rubber film across the pavement.

― Stress Pig (kate), Friday, 11 November 2005 16:57 (twenty years ago)

It was a combination of heat and freezing temperatures that weakened the space shuttle's O-ring, as proven by awesome Dr. Feynman. Basically,

"The night before the launch showed freezing temperature. Concerned with this, the NASA technician has measured the temperature prior to launch. The ambiant temperature was within the launch range, and shuttle got the green light to launch. However, NASA did not account for the fact the temperature "at the o-ring" was still below the launch range. The air was warm enough, but the o-ring hasn't thawed yet. What Dr. Feynman observed during his video forensic investigation was he saw a puff of black smoke come out of side of solid fuel rocket. He deduced that that must have been failed zinc-oxide putty and o-ring bits at the joint expelled out by hot gas. The tiny leak when the flame reach it acted as a torch against external tank and booster. Freed booster struct the main tank and pierced the tank's side. Liquid hydrogen Liquid oxygen fuels ignited. The Challenger was completely destroyed 73 seconds after the launch."

― jocelyn (Jocelyn), Friday, 11 November 2005 16:59 (twenty years ago)

It wasn't that the o-ring was weakened, but that the joint was not sealed properly because the o-ring couldn't deform due to the colder temps. Since the seal was not there, the exhaust gasses breached the joint and broke up the structure. Here's the link to the Roger's commission report: http://science.ksc.nasa.gov/shuttle/missions/51-l/docs/rogers-commission/Chapter-4.txt

Regardless, the o-rings didn't crumble, crack, or disintegrate due to cold temps. They simply weren't able to seal. They were destroyed by the combustion gases.

― Jaq (Jaq), Friday, 11 November 2005 17:06 (twenty years ago)

depends on the ground it lands on too. on concrete i'd say it'd probably break apart. on soft earth, probably leave an indentation and maybe bounce a little.

― AaronK (AaronK), Friday, 11 November 2005 17:55 (twenty years ago)

what about on a trampoline?

― Britain's Obtusest Shepherd (Alan), Friday, 11 November 2005 18:07 (twenty years ago)

Skydiving from 30,000 Feet
http://www.batnet.com/mfwright/mcdermott.jpg

― TOMBOT, Friday, 11 November 2005 18:10 (twenty years ago)

nice link :D

― Jdubz (ex machina), Friday, 11 November 2005 18:17 (twenty years ago)

Skydiving from 30,000 Feet

BFD. Badass at large Joe Kittinger skydived from 100,000 feet

http://www.wpafb.af.mil/museum/eagles/kitt-3.jpg

― Elvis Telecom (Chris Barrus), Friday, 11 November 2005 18:21 (twenty years ago)

not going to bounce.

― rrrobyn (rrrobyn), Friday, 11 November 2005 18:41 (twenty years ago)

"Okay, if we ignore air resistance then all the potential energy that the ball has before it is dropped will be transferred into kinetic energy right before it hits. If PE = mgh, where mass m is approx 200g, acceleration due to gravity g is 9.8 ms^2 and height h = 9144 metres, then the total KE of the ball right before impact will be approx 17.9 kJ. If all this kinetic energy is transferred into heat on collision, then I calculate that the final furious impact will have the same devastating consequences as would be unleashed by setting fire to a (standard size) Snickers bar."

nope, most of that gravitational potential energy would be lost as heat (and a little sound) through the air, and a little more lost on impact - so all that g.p.e. wont be converted to kinetic energy

― splates (splates), Friday, 11 November 2005 19:23 (twenty years ago)

4 ft. diameter ball of rubber bands gets dropped from 1 mile up - leaves huge crater, no bouncing.

― Jaq (Jaq), Friday, 11 November 2005 19:38 (twenty years ago)

http://www.wpafb.af.mil/museum/eagles/kitt-3.jpg
I'd rather the fire-storm of atmospheres
Than this cruel descent from a hundred years
Of dream, into the starkness of the capsule.
Two of our crew still lay suspended, cool
In their tombs of sleep. The nagging choirs
Of memory, the lenghts of tube, and wires
Worming from their flesh to machinery
I would have to cut. Such midwifery
Is just one function of the leader here:
Floating in a sac of fluid dark, a clear
Century of space away from Earth.
One man stared from the trauma of this birth
Attentive to the tapes asssuring him
This was reality, however grim:
Our journey's end. The landing itself
Was nothing. We just touched upon a shelf
Of rock selected by the Automind.
And left a galaxy of dreams behind.....

― Jdubz (ex machina), Friday, 11 November 2005 19:40 (twenty years ago)

that rubber band ball was stupid - the rubber bands all flew off on impact, thats why it didnt bounce. All the energy was split up between individual rubber bands as they flew off. Had they stayed together it would have bounced.

― splates (splates), Friday, 11 November 2005 19:49 (twenty years ago)

The huge crater in that story was smaller than the one-ton-plus ball of elastic bands dropped into the desert. Well, smaller if you believe the first diameter they give, larger if you believe the second one. That hardly qualifies as huge.

― Martin Skidmore (Martin Skidmore), Friday, 11 November 2005 20:39 (twenty years ago)

The first number (14 something feet) is the circumference. It threw me at first reading. The diameter of the ball was 4 feet, the diamter of the crater was 9 feet.

― Jaq (Jaq), Friday, 11 November 2005 20:43 (twenty years ago)

which, is more big than huge, agreed.

― Jaq (Jaq), Friday, 11 November 2005 20:44 (twenty years ago)

This is a good place to pose my question:

Does anybody know where I might order (inexpensively) something along the lines of 100-300 small bouncy balls for an art project?

I will also be buying thousands of yards of monofilament and bleached starfish carcasses, but I already have suppliers for these.

Your thoughts?

― pretentioRemy (x Jeremy), Friday, 11 November 2005 20:49 (twenty years ago)

Maybe Oriental Trading, though is $.30 each inexpensive?

― Jaq (Jaq), Friday, 11 November 2005 20:57 (twenty years ago)

Ahh… thanks! I can buy 1008 3/4" glow-in-the-dark bouncy balls for $34.65!

Man, that is SO cool!

― pretentioRemy (x Jeremy), Friday, 11 November 2005 21:00 (twenty years ago)

I like how they specify there are 12 items per dozen :)

― Jaq (Jaq), Friday, 11 November 2005 21:10 (twenty years ago)

Everyone's seen this right? What happens when you drop 10,000 super balls down a street in San Francisco.

― Elvis Telecom (Chris Barrus), Friday, 11 November 2005 21:30 (twenty years ago)

Full res version of the ad

― Elvis Telecom (Chris Barrus), Friday, 11 November 2005 21:31 (twenty years ago)

That just made my day!

― Jaq (Jaq), Friday, 11 November 2005 21:41 (twenty years ago)

ten years pass...

This tv ad for Slack has me so aggravated

https://www.youtube.com/watch?v=x6sSa5NpqUI

The downforce from the rotors would press directly on the umbrella surface and the thing would never get off the ground. Fuck you, animal team! Your idea is bullshit!

― bothan zulu (El Tomboto), Friday, 8 April 2016 03:08 (nine years ago)

You must be logged in to post. Please either login here, or if you are not registered, you may register here.