A crate of potatoes of mass 23.0 kg is on a ramp with angle of incline 30° to the horizontal. The coefficients of friction are μs = 0.78 and μk = 0.35. Find the frictional force (magnitude and direction) on the crate if the crate is at rest.

I don't understand why I am given both coefficients when it states the crate is at rest. I tried solving for static friction by doing normal force x the coefficient of static friction. That is wrong. I tried making it and equilibrium problem where the static friction and horizontal component of the weight = 0 but that just didn't make sense because I wouldnt even need the coefficient. Clearly I'm very lost. Please help!!!

1 answer

Tricky little problem makers. You don't need the coefficients after all. I got it!