Physics
posted by Teresa .
A 15 kg box sits on a horizontal force.
the coefficient of static fricition between the box and the surface is 0.70. if a force P is exerted on the box at an angle directed 37 degrees below the horizontal, what must be the magnitude of P to get the box moving??

break up the force into a vertical (downward) and horizontal. The component downward adds to the force of friction.
Forcefriction=(Psin37+15*9.8)*.70
So Pcos37 must equal this force, solve for P.