Describe the conditions under which a system’s angular velocity remains constant.

A system may exhibit rotational equilibrium (constant angular velocity) without being in translational equilibrium, and vice versa.

Free-body and force diagrams describe the nature of the forces and torques exerted on an object or rigid system.

Rotational equilibrium is a configuration of torques such that the net torque exerted on the system is zero. Relevant equation:

The rotational analog of Newton’s first law is that a system will have a constant angular velocity only if the net torque exerted on the system is zero.

A rotational corollary to Newton’s second law states that if the torques exerted on a rigid system are not balanced, the system’s angular velocity must be changing.