Question

A 75 force is applied to the side of a crate resting on a level floor. The crate has a mass of 25kg. If the coefficient of static friction is .15, is the 75 N force enough to make the crate accelerate? Explain why or why not.

Answer 1

If the coefficient of static friction is 0.15, then 0.15 of the crate's weight
shows up as a force resisting the horizontal pull.  So we really only
need to know the crate's weight.

Weight = (mass) x (gravity)  =  (25) x (9.8)  =  245 newtons.

0.15 of 245 newtons  =  36.75 newtons.

The force due to friction that's holding the crate back, not letting it start
sliding, is 36.75 newtons.  If you push it with 75 newtons of force, then
that  IS  enough to make the crate accelerate.