15. Rotational Equilibrium

A 3.0 m wood plank is supported by two scales. One scale is at the right end of the plank. The other scale is positioned such that it reads 620 N. If the mass of the plank is 85 kg, how far is the second scale from the right end of the plank?

Suppose a certain car has a track width of 1.6 m and a center of gravity located 0.40 m above the center of the track. What is the critical angle for this car?

A 15,000-N crane pivots around a friction-free axle at its base and is supported by a cable making a 25° angle with the crane (Fig. E11.18). The crane is 16 m long and is not uniform, its center of gravity being 7.0 m from the axle as measured along the crane. The cable is attached 3.0 m from the upper end of the crane.

When the crane is raised to 55° above the horizontal hold-ing an 11,000-N pallet of bricks by a 2.2-m, very light cord, find (a) the tension in the cable. Start with a free-body diagram of the crane.

FIGURE P12.63 shows a 15 kg cylinder held at rest on a 20° slope. b. What is the magnitude of the static friction force?