You throw a Frisbee of mass m and radius r so that it is spinning about a horizontal axis perpendicular to the plane of the Frisbee. Ignoring air resistance, the torque exerted about its center of mass by gravity is
A) 0.
B) mgr.
C) 2mgr.
D) a function of the angular velocity.
E) small at first, then increasing as the Frisbee loses the torque given it by your hand.

Question

Quizplus · Accepted Answer

The torque exerted about the center of mass by gravity is 0 because the force of gravity acts through the center of mass, resulting in no lever arm to create torque.

You Throw a Frisbee of Mass M and Radius R