1.

A stroboscope is a light that ashes on and off at a constant rate. It can be used to illuminate a rotating object, and if the ashing rate is adjusted properly, the object can be made to appear stationary. (a) What is the shortest time between ashes of light that will make a three-bladed propeller appear stationary when it is rotating with an angular speed of 21.6 rew's? {b} What is the next shortest time? A figure skater is spinning with an angular velocity of +18.3 rad/s. She then comes to a stop over a brief period of time. During this time, her angular displacement is +5.38 rad. Determine (a) her average angular acceleration and (b) the time during which she comes to rest