Question

A person throws 0.1kg a ball at a brick wall.The ball hits the wall perpendicular with a speed of 4m/s .calculate the change in momentum of the ball.

Answer 1

Mass of ball is 0.1 kg
velocity of ball is 4m/s

momentum in going towards wall=mv
momentum in returning from wall=(-mv)

change in momentum will be

=mv-(-mv)=2mv

so change in momentum=2×0.1×4
=>0.8

Answer 2

mass = 0.1kg
velocity = 4m/s
momentum = m×v
p= mv
p= 0.1×4 = 0.4kgm/s