A disk, a hoop, and a solid sphere are released at the same time at the top of an inclined plane. They are all uniform and roll without slipping. In what order do they reach the bottom?
A) sphere, hoop, disk
B) hoop, disk, sphere
C) sphere, disk, hoop
D) hoop, sphere, disk
E) disk, hoop, sphere

Question

Quizplus · Accepted Answer

The moment of inertia is lowest for the sphere, higher for the disk, and highest for the hoop. Lower moment of inertia means more of the potential energy is converted into translational kinetic energy rather than rotational, allowing the sphere to reach the bottom first, followed by the disk, and then the hoop.

A Disk, a Hoop, and a Solid Sphere Are Released