A box of mass 25kg is sitting on a horizontal plane and has a normal force pointing down of 31N, and the coeff of kinetic and static friction between the box and floor are .22 and .38, respectively. What is the min horizontal force F needed to make the box start moving?

Answer 1

Fn = 31N. = Normal force.

Fs = u*Fn = 0.38 * 31 = 11.78 N. = Force of static friction.

F-Fs = M*a.
F-11.78 = 25*0
F = 11.78 N.