A ball with mass $m$ is at rest when it is struck by a bat. After impact, the ball moves away from the bat with velocity $v$. The bat stays in contact with the ball for a brief interval $\Delta t$. What is the average force exerted by the bat on the ball?
- A$mv\Delta t$
- B$\dfrac{mv}{\Delta t}$
- C$\tfrac{1}{2}mv^2\Delta t$
- D$\dfrac{\tfrac{1}{2}mv^2}{\Delta t}$