1. The problem statement, all variables and given/known data The block shown in Fig. P-223 is acted upon by its weight W = 200lb, a horizontal force Q = 600lb and the pressure P exerted by the inclined plane. The resultant R of these forces is up and parallel to the incline thereby sliding the block up it. Determine P and R. Hint: Take one axis parallel to the incline. Ans: R = 293lb https://fbcdn-sphotos-h-a.akamaihd.net/hphotos-ak-xpf1/v/t1.0-9/q82/s720x720/11015301_1002403293112217_141332182178751666_n.jpg?oh=13938518c6c5618236be3f0fbd8ce4aa&oe=562F0B00&__gda__=1445053718_99ad9a3e011c3cbad300e49a737ea336 2. Relevant equations R = SummationFx + SummationFy Fx = Fcos0 Fy = Fsin0 3. The attempt at a solution I don't know how to start the problem. In the worktext, this is the only problem that has unknown magnitude(P). To get the R I need first to P. The hint says take one axis parallel to the incline, I will be able to form an isosceles triangle with P as the leg but I still won't be able to solve for the magnitude of P.... How do I start this problem? This problem is from Engineering Mechanics by Singer, it is our homework #213-223, I'm already done with the rest. The previous problems has all given magnitude and angle(some you need to solve for the angle, but still are easy except this one because of unknown value of P).