Under what conditions can a rotating body be in equilibrium? Give an example.
The conditions for a body to be in equilibrium are,
(a) The net external force on the body has to be zero
(b) The net external torque on the body has to be zero.
Step 1 of 2
Equilibrium position means the body is either at rest or in a motion with a constant velocity. The net external force acting on the body is zero. The equilibrium condition is disturbed when an unbalanced external force acts on the system.
For a body rotating about an axis, it is in equilibrium if it is at rest (not rotating) or it is rotating at a constant angular velocity about the axis. It means that the body will not have any angular acceleration during its rotation. For angular acceleration to be zero, the net net external torque on the body has to be.
Therefore, the necessary conditions for a rotating body to be in equilibrium are,
(a) The body is not subjected to any external force.
(b) The body is not subjected to any external torque.