Question 3

3. Rotations. Consider a large uniform metal disc in a factory with radius 2m and mass 100kg (moment of inertia Idisc = {me?). The disc is oriented horizontally (level with the floor) and rotates around its center without friction. At t = 0 the disc starts from rest, and a motor is turned on that applies a constant torque of 1000 N m to the disc to spin it around its center. A. Find the magnitude of the angular acceleration of the wheel after the motor is turned on. B. How many revolutions does the system go through in the first 10 seconds? C. How much work does the motor do in the first 10 seconds? What is the average power of the motor during this time