Question

A bodyof mass 0.4 if is thrown against a brick wall.when it strikes the wall,it is moving horizontally to the left at 30 m/ s,and it rebounds horizontally to the right at 20 m/ s.find;the change in momentum of ball,magnitude and sign of impulse of the force exerted on the ball,direction of force acting on the ball

Answer 1

initial momentum = 0.4(-30) = -12 kg m/s
final momentum = 0.4 (+20) = +8 kg m/s
change = +8 - -12 = +20 kg m/s
force and impulse to right. impulse = change of momentum and force = impulse / time in contact with wall