A block is being held in place on a frictionless surface. The block has a mass of 3.9 kg and is held in place on an incline of angle = 32° by a horizontal force F, as shown in the figure below. (a) Find the magnitude of the normal force
(b) Find the magnitude of F. (Ignore friction)

The bar of prob. 5/82 is repeated here. the ends of the 0.4-m bar remain in contact with their re- spective support surfaces. end b has a velocity of 0.5 m/s and an acceleration of 0.3 m/s2 in the di- rections shown. determine the angular accelera- tion of the bar and the acceleration of end a.