This question is driving me nuts. I really need help with it, actually i just need help setting up my equations. Mu = the weird friction sympol A box of a mass m=22 kg is at rest on a ramp inclined at 45 degrees to the horizontal. The coefficient of friction between the box and the ramp are "Mu s" = 0.78 and "Mu k" = 0.65. a)Determine the magnitude of the largest force that can be applied upward, parallel to the ramp, if the box is to remain at rest. My equation are: Fn=Fgy - Fapp Fnet = 0 also Fnet = Fgx - Ffs After that i end up getting two equations for Fapp but when i solve for it i get a negative answer. I also tried flipping Fapp so Fn=Fapp - Fgy but that also won't work, i get the wrong answer. So can anyone please help get my two equations, theres something wrong with mine.