Question

A $250g$ball collides with a wall. FIGURE EX11.13 shows the ball’s velocity and the force exerted on the ball by the wall. What is $v_{fx}$, the ball’s rebound velocity?

Short answer

The rebound velocity of ball$6m/s$.

Step-by-step solution

Given information  

We need to find the rebound velocity of ball.

Simplify 

By using the impulse-momentum theorem, we can assume collisions are elastic. Initial velocitiy $v_{ix}=-10m/s$showm in figure left and in the right figure $J_x=(500N\times 0.008s)=4Ns$

So we have

$$\begin{gathered} p_{fx}=p_{ix}+J_x \\ m{v}_{fx}=m{v}_{ix}+J_x/:m \\ {v}_{fx}=v_{ix}+\frac{J_x}{m}=-10m/s+\frac{4Ns}{0.250kg}=6m/s. \end{gathered}$$