Question

Whats the difference between the formulas for kinetic and static friction.

Kinetic:
Ff= ukFn

Static:
Ff= usFn

Are the 'f' and the 'n' the mass of the object?

Are the 'k' and the 's' just the

Answer 1

The f and the n are subscripts that stand for "friction" and "normal"

k and s are subscripts of "u" that denote "kinetic" and "static"

It is too bad that the computer tools available to us here do not permit subscripts.

Answer 2

to find the frictional force you would take the coefficient x the weight?

Answer 3

Ff is force friction. Fn is the normal force, not the mass of the object. The normal force does depend on the weight of an object, which ultimately depends on the mass.

Although there is no difference in the actual equations for physics, there is a difference between kinetic and static friction. Say if you start pushing a box, kinetic friction is the friction between between the ground and the box when the box is moving, and static friction is the friction you need to overcome to start moving the box.

Hope this helps!

Answer 4

Thanks Drwls & Carlie :)