# Friction between rotating objects

In physics, we learned about friction between one object sliding across another, but when we got to torque and angular velocity, etc, there was never any mention of how to calculate friction between 2 objects rotating in place. Say you have a plate on top of a table and it is rotating about the center of the plate. How would you calculate the friction between the plate and the table if the coefficient of friction is known?

## Answers and Replies

malawi_glenn
Homework Helper
change to spherical coordinates and integrate over the surface.

tiny-tim