Question

The force of gravity acts on the baton in the given figure, and forces produce torques that cause a body’s angular velocity to change. Why, then, is the angular velocity of the baton in the figure constant?

Short answer

The baton rotates with constant angular velocity because the gravitational force acting on its centre of gravity causes no torque about that location.

Step-by-step solution

Centre of gravity

A body's centre of gravity is the location at which all of its gravitational torque is zero.

Identification of given data

Here we have given one figure and say that The force of gravity acts on it. And forces produce torques that cause a body’s angular velocity to change.

Finding why forces produce torques that cause a body’s angular velocity to change

This baton is located in a roughly homogeneous gravitational environment where the centres of mass and gravity are identical. The torque of gravitational forces operating on all portions of the baton are entirely balanced, resulting in a net torque of zero and a rotation with a constant angular velocity since the baton is spinning about the centre of gravity, which is defined as the point through any axis containing it.