Friction Friction results from relative

motion between objects. Frictional forces are forces that

resist or oppose motion.

Coefficient of friction ()

—Feet on rocks = large

—Polar bear on ice = small

Friction(A Fun Formula)

Ff = Fnfun

get it?

Friction(A Fun Formula)

Ff = Fn

Normal force (N)

Coefficient of frictionNo units!

Friction force (N)

Friction

Ff = Fn=FfFnFn =

Ff /

To solve for frictional force

To solve for normal force

To solve for coefficient of friction

Calculate force of friction

A box weighs 100 N (Fn).

As the box is pushed horizontally, the coefficient of sliding friction is 0.25.

Determine the force of friction resisting the motion.

To solve for frictional force:

Ff = Fn

Fn = 100 N Ff = (0.25)(100 N) Ff = 25 N