A rod rests on frictionless ice. Forces that are equal in magnitude and opposite in direction are simultaneously applied to its ends as shown. The quantity that has a magnitude of zero is its:
A) angular momentum
B) angular acceleration
C) total linear momentum
D) kinetic energy
E) rotational inertia

Question

A rod rests on frictionless ice. Forces that are equal in magnitude and opposite in direction are simultaneously applied to its ends as shown. The quantity that has a magnitude of zero is its: 
A) angular momentum 
B) angular acceleration 
C) total linear momentum 
D) kinetic energy 
E) rotational inertia

Quizplus · Accepted Answer

The net force acting on the rod is zero, so the total linear momentum of the system is conserved and stays at zero. However, the other quantities listed (angular momentum, angular acceleration, kinetic energy, and rotational inertia) are all non-zero.

A Rod Rests on Frictionless Ice