# Friction Force Between Steel and Teflon| Further Applications of Newton’s Laws: Friction, Drag, and Elasticity| College Physics| Problem 5.1

### A physics major is cooking breakfast when he notices that the frictional force between his steel spatula and his Teflon frying pan is only 0.200 N. Knowing the coefficient of kinetic friction between the two materials, he quickly calculates the normal force. What is it?

#### SOLUTION:

Shown below is the table for the coefficient of static and kinetic friction copied from the book. The coefficient of kinetic friction with the system Teflon on steel is 0.04.

To solve for the unknown normal force, we shall use the formula for friction

$f=\mu _kN$

Solving for N, we have

$N=\frac{f}{\mu _k}$

$N=\frac{0.200\:N}{0.04}$

$N=5.00\:N$

The normal force is 5.0 Newton.