Question
A hockey ball of mass 200 g travelling at 10 ms-1 is struck by a hockey stick so as to return it along its original path with a velocity at 5 ms–1. Calculate the change of momentum occurred in the motion of the hockey ball by the force applied by the hockey stick.
Solution
Here,
Mass of the hockey ball, m = 200 g = 0.2 kg
Initial velocity of the ball, u = 10 ms-1
Final velocity, v = -5 ms-1
So, change in momentum = m(v - u)
= 0.2(-5 - 10)
= -3 kg ms-1.
