PHYSICS
posted by Anonymous .
A crate of potatoes of mass 9.0 kg is on a ramp with angle of incline 30° to the horizontal. The coefficients of friction are μs = 0.69 and μk = 0.41. Find the frictional force (magnitude and direction) on the crate if the crate is at rest.
magnitude N?
thanks

friction up the plane: mg*mu*cosTheta

DO i use uk or us for u cuz i used both n it was wrong
I put 9(9.8)x9(.69)(.41)cos(30) :/ 
please help me i am stuck