4. A turntable rotates at a constant speed around a central vertical axis with an angular speed wo. The turntable has a moment of inertia I = 5 x 10-5 kg m about the axis. Sand particles fall onto the turntable at a rate of 1 gram per second and adhere to the surface, forming a circle with a radius r = 0.1 m. See the right Figure. Find the time it takes for the sand particles to fall onto the turntable and cause its angular velocity to change to wo/2. 5. Two skaters A and R have B01