# Kinetic Friction

Written by Jerry Ratzlaff on . Posted in Fluid Dynamics

Kinetic friction is the force opposing two objects rubbing together that are moving relative to each other.

## Kinetic Friction formula

$$f_k = \mu_k F_n$$

Where:

$$f_k$$ = kinetic friction

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

$$F_n$$ = normal force

Solve for:

$$\mu _k = \frac {f_k}{F_n}$$

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