1. A spherical disk is rolling down a hill. At the midway point, select all of the types of energy which the disk possesses. (a) Rotational kinetic energy (b) Translational kinetic energy (c) Gravitational potential energy (d) Elastic potential energy. 2. Two masses, each 2kg, are attached via a 4m massless rod. The rod is spinning such that the masses are rotating around in a circle m. What is the moment of inertia l, in kg m^2 of the system? You should that assume l= mr^2 for each mass, and that the axis of rotation is through the center of the rod