A woman throws an object of mass 500 g with a speed of `25 m s^(-1)` .
(a) What is the impulse imparted to the object ?
(b) If the object hitts a wall and rebounds with the half the original speed , what is the change in momentum of the object ?

Explanation

Here, ` m = 500 g = (1)/(2) kg , u = 25 ms^(-1) `
(a) Impulse imparted = change in momentum = initial momentum given ` m u = (1)/(2) xx25 = 12.5 Ns `
(b) On rebounding force the wall ` upsilon = -(1)/(2) xx 25 = - 12.5 m//s `
Change in momentum ` = m (upsilon- u ) = (1)/(2) (-12.5- 25) = - 18.75 kg ms^(-1)` .