$3$

Mark for Review

A solid, uniform disk is spinning about an axis through its center while its center of mass remains at rest. Which of the following correctly describes the disk's kinetic energy $K,$ and provides supporting reasoning?

A $K$ is zero. The velocity of the disk's center of mass is zero.

$K$ is zero. For every point on the disk moving with a translational velocity vec$(v),$ there is another point on the disk moving with the opposite velocity $-$vec$(v).$

$K$ is greater than zero. The disk's mass and rotational inertia are both greater than zero.