Posted by Daniella on .
ohh sorry, in my first question...
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??
``IT SHOULD BE A 15 kg box sits on a horizontal SURFACE and not A 15 kg box sits on a horizontal FORCE....

Physics 
Damon,
We did this problem for you below. I have a typo
force down is 15*9.8 not 15
WLS did it all out for you. 
Physics 
Damon,
force down = 15 * 9.8 + P sin 37
force horizontal = P cos 37
0.7 (15 * 9.8 + P sin 37) = P cos 37 
Physics 
Damon,
We both assumed that you meant horizontal surface.

Physics 
Daniella,
ok...thanks a lot.....