Problem 310 - 311 | Equilibrium of Concurrent Force System

Problem 310
A 300-lb box is held at rest on a smooth plane by a force P inclined at an angle θ with the plane as shown in Fig. P-310. If θ = 45°, determine the value of P and the normal pressure N exerted by the plane.
 

Block supported by a force in the incline

 

Solution 310

 

Problem 311
If the value of P in Fig. P-310 is 180 lb, determine the angle θ at which it must be inclined with the smooth plane to hold 300-lb box in equilibrium.
 

Solution 311