Chapter 10, Problem 10.78P

The solid wood door of a gymnasium is 1.00 m wide and 2.00 m high, has total mass 35.0 kg, and is lunged along one side. The door is open and at rest when a stray basketball hits the center of the door head-on, applying an average force of 1500 N to the door for 8.00 ms. Find the angular speed of the door after the impact. [Hint: Integrating Eq. (10.29) yields $\Delta L_z={\displaystyle {\int }_{t_1}^{t_2}(\sum {\tau }_z})dt={(\sum {\tau }_z)}_{av}\Delta t$. The quantity ${\displaystyle {\int }_{t_1}^{t_2}(\sum {\tau }_z})dt$ is called the angular impulse.]