# Kinetic Friction Coefficient

Written by Jerry Ratzlaff. Posted in Dimensionless Numbers

Kinetic friction coefficient is a dimensionless number, the amount of force that resists motion at a constant velocity.

## FORMULA

$$\mu_k = \frac {f_k}{F_n}$$

Where:

$$\mu_k$$ (Greek symbol mu) = kinetic friction coefficient

$$f_k$$ = kinetic friction

$$F_n$$ = normal force