Question
When a ball of mass m moving with velocity u collides elastically with a wall normally, then what is the change in momentum of the ball?
Solution
Initial velocity of the ball =u
Mass of the ball = m
So, initial momentum of the ball = m u
After collision, the ball changes it's direction.
Therefore, momentum = - mu
Therefore,
Change in momentum of the ball = mu - (- mu) = 2mu.
Mass of the ball = m
So, initial momentum of the ball = m u
After collision, the ball changes it's direction.
Therefore, momentum = - mu
Therefore,
Change in momentum of the ball = mu - (- mu) = 2mu.
