A ball of mass m strikes a wall that is perpendicular to its path at speed +v and rebounds in the opposite direction with a speed -v.The impulse imparted to the ball by the wall is
A)2mv
B)mv
C)zero
D)-mv
E)-2mv

Question

Quizplus · Accepted Answer

The impulse imparted to the ball by the wall can be calculated using the equation:

impulse = change in momentum

Since the momentum of the ball changes from mv (in the positive direction) before the collision to -mv (in the negative direction) after the collision, the change in momentum is:

Δp = (-mv) - (mv) = -2mv

Therefore, the impulse imparted to the ball by the wall is equal to:

impulse = Δp = -2mv

which corresponds to choice E.

A Ball of Mass M Strikes a Wall That Is