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Noddy


Noddy

Toe Poking Bad Boy
Location: Lake District UK

Total posts: 2865
Posted:this is an argument which we have on our way to the juggling club:

if i was to throw a juggling ball up in the air while i was in the car and i was throwing the ball with my arm out of the window, and there was no air friction, would the ball go up then back down to my hand? or ill the car have moved me away? or even will the ball just keep oing upwards

this has caused alot of arguments

whats your verdict?


Remember.........YOU LOSE!!!

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.:star:.
SILVER Member since Jan 2005

.:star:.

Pooh-Bah
Location: Bristol

Total posts: 1785
Posted:The ball would fall into your hand....providing that you can throw straight!



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Pele
BRONZE Member since Dec 2000

Pele

the henna lady
Location: WNY, USA

Total posts: 6193
Posted:Even with no air friction, gravity would still be in effect, so I believe it would come back down but with the forward motion of the car, you would not be there to catch it.

Pele
Higher, higher burning fire...making music like a choir
"Oooh look! A pub!" -exclaimed after recovering from a stupid fall
"And for the decadence of art, nothing beats a roaring fire." -TMK

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oli
SILVER Member since Jul 2003

not with cactus
Location: bristol/ southern eastern devo...

Total posts: 2052
Posted:well im not sure. but if i thinklogically, the ball is traveling foreards at the same speed as the car while you are holding it. once its thrown the only thing that can slow it down is air resistance. you say there is no air restistance so the ball cannot slow down, therfore it will continue to move with a constant horizontal velocity. so if the car moves at the same constant velocity (no acceleration) while the balls in the air, it should just fall back you your hand. smile

now i am a very sleepy oli though cool


Me train running low on soul coal
They push+pull tactics are driving me loco
They shouldn't do that no no no

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.:star:.
SILVER Member since Jan 2005

.:star:.

Pooh-Bah
Location: Bristol

Total posts: 1785
Posted:You'd catch it...Oli is correct.... biggrin



Written by: from a physics site




Question - My 10 years old son wants to know If a person jumps (or

throws an object straight up) inside of a moving object (plane, train,

others) traveling fast will it land on the same spot theoretically?

(Assume time in the air to be long).

----------------

Sia -



Yes, if the vehicle is in straight-line, unaccelerated motion the object

will land in the same spot from which it was launched. Try it in your car.

Then try it with the car accelerating or braking.



If you think about it, we are moving on the surface of the earth. ( This

motion is unaccelerated and almost straight line.) When you through a ball

straight up it will come straight down to the original position.



This is related to Newton's first law of motion - inertia. You might want

to read more about it.



Larry Krengel

=====================================================

The best thing is to try this yourself. After all, that is how people

figured all this out in the first place. But to answer, if the car is

going along steadily, then the ball will never "know" (windows rolled up

of course). But if the driver hits the gas just as you throw it up,

then things might be a bit different, the ball might fall behind, and

seem to come back towards the rear of the car.







http://www.newton.dep.anl.gov/askasci/phy00/phy00855.htm


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Noddy


Noddy

Toe Poking Bad Boy
Location: Lake District UK

Total posts: 2865
Posted:but your throwin the ball outside the car

Remember.........YOU LOSE!!!

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.:star:.
SILVER Member since Jan 2005

.:star:.

Pooh-Bah
Location: Bristol

Total posts: 1785
Posted:ooooh i misread that bit..silly me! redface



although...without air resistance, you should still catch it, i think. Its the same as the example above because the car is protecting you from the air resistance, so being outside the car without air resistance should be the same.

EDITED_BY: .:star:. (1118611335)


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Caben


Caben

Taster of beer, drinker of wine and all around stumbler.
Location: Somewere way out there

Total posts: 238
Posted:You would catch it, if you had less than 3 beers...after that it is all up to the god of grog

A high powered mutant of some kind never even considered for mass production. Too weird to live and too rare to die.

a crowded elevator smells different to a midget

If you take me seriously you would be the only one

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.Morph.
SILVER Member since Mar 2002

.Morph.

addict
Location: Lancashire, UK

Total posts: 669
Posted:what Pele said
juggle


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UCOF
SILVER Member since Apr 2002

UCOF

Carpal \'Tunnel


Total posts: 15414
Posted:I will only believe what Cole or vanize, or someone equally knowledgeable in this field says.

smile


I think you wont catch it though, unless you throw it up and forwards a bit confused


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Stout
SILVER Member since May 2004

Stout

Pooh-Bah
Location: Canada

Total posts: 1872
Posted:Yep...Oli got nailed it

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Posted:Once the ball is in the air, there are no horizontal forces acting upon it (no air resistance), so it won't accelerate horizontally (Newton I and II). Therefore, its horizontal velocity will be constant and equal to that of the car, and you will catch it.

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Dom
BRONZE Member since Dec 2001

Dom

Carpal \'Tunnel
Location: Bristol, UK

Total posts: 3009
Posted:Yep, you'll catch it.
The principal works the same way if you jumped up high in an aeroplane - you don't go smashing into the back of the plane at 500 miles an hour!! eek


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coleman
SILVER Member since Aug 2002

coleman

big and good and broken
Location: lunn dunn, yoo kay

Total posts: 7330
Posted:yep, star and oli are right.



throwing a ball up on the outside of a car moving at a constant speed with no air outisde (hence no air resistance) is equivalent to throwing it up inside the car.



normally, the only difference between the inside and outside of the car for a test like this is that outside there's loads of air rushing past and inside, the air is moving along at the same speed as the car.



the advantage of realising the equivalence is that by doing the test inside a normal car (with air outside and all that), you are saved the need of finding a vacuum big enough to drive your car along in to find out the result.



smile





cole. x


"i see you at 'dis cafe.
i come to 'dis cafe quite a lot myself.
they do porridge."
- tim westwood

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UCOF
SILVER Member since Apr 2002

UCOF

Carpal \'Tunnel


Total posts: 15414
Posted:That'll do.

wink


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Noddy


Noddy

Toe Poking Bad Boy
Location: Lake District UK

Total posts: 2865
Posted:thanx guys i will use this agains my fellow jugglers on the way to the club wink

Remember.........YOU LOSE!!!

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Brian:-)
BRONZE Member since Jun 2004

Brian:-)

stranger
Location: London

Total posts: 37
Posted:Noddy,
Think of it this way. You are standing on a planet that is rotating at 700MPH. (At the latitude of the UK.) Not to mention wizzing in its path around the Sun. Lost any balls lately?


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