Math Is Fun Forum

duellers

Guest

kinematics problem

a ball is fired at a wall. when it hits the wall, it is moving at 6.0 metres per second. the ball is in contact with the wall for 0.04 seconds. when the ball bounces off the wall, the speed is 4.4 metres per second.

is this the right way to do this

v = u + at
-4.4 = 6 + 0.04a

so a = -225 metres per second squared??

seems wrong to me..

duellers

Guest

Re: kinematics problem

sorry should be a = -260ms^-2???

Bob

Administrator

Registered: 2010-06-20

Posts: 10,649

Re: kinematics problem

hi duellers,

Yes -260. 

It is large, but look at how quickly it's velocity has changed.

That's why those test crash dummies end up in such a mess. 

Bob

Last edited by Bob (2011-09-15 10:32:32)

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