Question

A figure skater begins spinning counterclockwise at an angular speed of 4.3 π rad/s. During a 5.0 s interval, she slowly pulls her arms inward and finally spins at 7.7 π rad/s. What is her average angular acceleration during this time interval? Answer in units of rad/s 2 .

Answer 1

$$\alpha=\dfrac{\omega_2-\omega_1}{5}=2.14\text{ rad/s}.$$