A tennis ball of mass 58g is moving horizontally,at right angles to the net,with a speed of 20ms/1.A player ?

Question

hits it straight back so that it leaves his racket with a speed of 25ms/1.what is

1)the size of the change of momentum of the ball

2)the impulse of the force which the racket exerts on the ball

please explain your answer

any help will be appreciated

Answer 1

1)

Impulse = Change in Momentum

Impulse = Momentum After - Momentum Before

Impulse = MVf - MVi

Impulse = 0.58kg(-25m/s) - 0.58kg(20m/s)

Impulse = - 26.1 kgm/s

2)  Impulse = - 26.1 Nsec

Hope this helps.

teddy boy