A student spins a bicycle wheel while its axle is held fixed so that the wheel’s…
PHYSICS · Single correct · AP · Physics 1: Algebra-based · Energy and Momentum of Rotating Systems · Energy and Momentum of Rotating Systems
Problem
A student spins a bicycle wheel while its axle is held fixed so that the wheel’s center of mass remains at rest relative to the room. Which of the following best explains why the wheel still has non-zero kinetic energy?
(a) The wheel’s large moment of inertia lets it store kinetic energy even when its mass is motionless, so the wheel retains energy despite the centre of mass being at rest.
(b) The centre of mass has rotational motion instead of translational motion, so kinetic energy exists only because the centre of mass is rotating in place.
(c) The points on the rim move through space, each with a non-zero linear speed, so the wheel possesses kinetic energy even though its centre of mass is stationary.
(d) Gravitational potential energy stored in the upper portions of the wheel is continually converted into kinetic energy as the wheel spins.