A hoop, a uniform disk, and a uniform sphere, all with the same mass and outer radius, start with the same speed and roll without sliding up identical inclines.Rank the objects according to how high they go, least to greatest.
A)hoop, disk, sphere
B)disk, hoop, sphere
C)sphere, hoop, disk
D)sphere, disk, hoop
E)hoop, sphere, disk

Question

Quizplus · Accepted Answer

The height each object reaches on the incline depends on its rotational inertia. A hoop has the largest rotational inertia, followed by a disk, and then a sphere has the smallest. Objects with larger rotational inertia convert more of their kinetic energy into rotational motion, leaving less energy for potential energy at a height. Therefore, the hoop goes the least high, the disk goes higher, and the sphere goes the highest.

A Hoop, a Uniform Disk, and a Uniform Sphere, All