Wednesday
February 10, 2016

Homework Help: momentum/impulse

Posted by Kim on Sunday, October 15, 2006 at 10:43am.

The following data concerns a tennis ball at a given instant before it is struck by a tennis racket;
horizontal momentum of tennis ball= 2.4Ns
kinetic energy of ball= 45J

a) why is correct to give the direction of the momentum but not the kinetic energy

b) write down in terms of the mass m and the velocity v of the body, expressions for
i) momentum
ii) the kinetic energy

c) use your answer to (b) to help calculate the mass and the velocity of the ball

d) when teh racket hits the ball it strikes it with a constant force of 60N in a direction opposite to its momentum, ringing to rest momentarily
calulate
i)the time the tennis ball takes to stop
ii) the distance the tennis ball travels while stopping

e) the force of 60N then contiues to act on the tennis ball for a further 0.60s. calculate
i) the momentum of the ball
ii)the distance the tennis ball travels while stopping