A 90 kg man is standing still on frictionless ice. His friend tosses him a 10 kg ball, which has a horizontal velocity of 20 m/s. After catching the ball, what is the man's velocity?

1 Answer
Jan 15, 2016


2 #m/s#


Using Law of Conservation of momentum.
Initial momentum is equal to final momentum
Momentum = #M_(man). v_(man)+m_(ball).v_(ball)#

Initial momentum = #90 times 0+ 10 times 20#

After the man catches the ball both ball and man move with the same velocity. Therefore
Final Momentum = #(M_(man)+m_(ball)). v_(fi nal)#
Equating the two

#200= 100 times v_(fi nal)#