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

Question

Quizplus · Accepted Answer

The solid sphere will reach the bottom first because it has the maximum moment of inertia, so it will rotate more slowly than the disk and the hoop. The disk and the hoop have similar moments of inertia but the hoop has more mass distributed further from the center, so it will rotate more slowly than the disk. Therefore, the order will be sphere, disk, hoop.

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