A solid sphere of mass 2.5 kg and a radius 0.15m starts from rest at the top of the a ramp inclined 15 degrees, and rolls to the bottom without slipping. The upper end of the ramp is 0.85m higher than the lower end. What is the total kinetic energy of the sphere when it reaches the bottom of the ramp?
a) if a wheel is turning at 1.2 rad/s, how much time does it take to complete one revoution?
b) A wheel initially has an angular velocity of 18 rad/s but it is slowing at a rate of 2.0 rad/s^2 until it comes to a stop. By the time it stops, how many radians will it have turned through?