For an object to have acceleration, it must be actedupon by a net force greater than 0 N. Imagine pushing a refrigerator across a room. Your pushing is a force in one direction. For the fridge to move, the force of your push must be greater than which forces?

Question

anonymous · Answer

$$F>\mu.m.g$$

anonymous · Answer

which is also known as friction

kainui · Answer

|dw:1344921631088:dw| So for the fridge to move the applied force (Fapp) needs to be greater than the opposing force of static friction (Fs). So what is Fs?$$F _{s}=\mu _{s}n$$ where mu (the greek letter) is the coefficient of static friction which depends on the material of the objects, and is looked up on a chart and "n" the normal force. The normal force is just the force opposite and equal to the force of gravity, F=mg.

So plug it all in and you get

Fs=Fapp
Fs=u*n
n=Fg
Fg=mg

Fapp=umg

So the force you apply is based on the coefficient of static friction, the mass of the object, and acceleration due to gravity.