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Author Topic: Kicking a football  (Read 2777 times)

Les the Scientist

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Kicking a football
« on: 25/05/2005 21:02:14 »
How much faster does a ball leave the foot when it's kicked?  With the ball being under pressure it will spring off the boot faster than the speed of the foot.  But how much faster ?

ukmicky

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Re: Kicking a football
« Reply #1 on: 26/05/2005 01:44:01 »
dont know the maths but i would of thought there would be to many variables over the force of impact to give an awnser to the question
like. angle of attack. weight of the boot. strength of muscles, shape of the boot.air temperature, air presure, air presure in the ball,size of ball, type of ball, etc, etc

daveshorts

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Re: Kicking a football
« Reply #2 on: 26/05/2005 21:29:04 »
I think if the ball starts of stationary, is much lighter than the foot, and no energy is lost it will end up moving at up to twice as fast as the foot did.

If you were moving at the same speed as the centre of mass of the whole system, you would see both the foot and the ball move towards the collision and bounce off at the same speed they started with.

If the ball is light the centre of mass is moving at about the same velocity as the foot.

So sitting at the centre of mass moving at 'v' you would see the ball move towards you at 'v', and then move away from you at '-v'.

If you are outside you see the ball stationary to start with and then move away at '2*v'.

If that wasn't clear I will try and draw some diagrams.

DoctorBeaver

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Re: Kicking a football
« Reply #3 on: 26/05/2005 21:59:35 »
The way I kick a football it hardly moves at all

The Naked Scientists Forum

Re: Kicking a football
« Reply #3 on: 26/05/2005 21:59:35 »