FRICTION - form 2

 ~ friction = force that opposes motion.
 ~occurs whenever 2 surfaces rub against each other.
 ~ has direction and magnitude.

 ~ friction can :
 (a) prevent a statinary object from moving.
 (b) slow down or stop moving object.

 ~the magnitude of the frictional force depends on :
 (a) the nature of the surface.
*the rougher the surfaces, the greater the frictional force between them.
 (b) the weight of the object.
*the heavier the object,the greater the frictional force acting on it.