A student spins a rigid wheel of mass M about its center with angular speed ω while holding the center of mass fixed relative to the ground. Which statement best describes the wheel’s kinetic energy during this motion?
a) It possesses both translational and rotational kinetic energy because points on the rim of the wheel move through space.
b) It possesses only translational kinetic energy because every mass element has a linear speed v=rω.
c) It possesses only rotational kinetic energy because the center of mass is not translating.
d) Its rotational kinetic energy is 21Mω2, since the mass M appears directly in the formula.