Q. A grinding wheel is initially at rest. A constant external torque of 45.8 N· m is applied to the wheel for 18.8 s, giving the wheel an angular speed of 596 rev/min. The external torque is then removed, and the wheel comes to rest 129 s later. Find the moment of inertia of the wheel.
Q. A minivan moving at 38 m/s passes an unmarked state police car moving at 24 m/s. The electromagnetic waves produced by the radar gun in the police car have a frequency of 8.25 × 10^9 Hz. What is the magnitude of the difference in frequency between the waves emitted by the gun and those that are reflected back from the speeding minivan?