A hollow sphere (mass = m, radius = r) rolls down a 45-degree incline. Let be the angle of rotation of the sphere, and = the angular velocity = /t. (i) Write the total kinetic energy of the sphere in terms of . (ii) Write the gravitational potential energy in terms of . (iii) The total energy has the form 1/2 ^2 - , so use part A to determine the angular acceleration