Equilibrium of a Rigid Body - General Questions

The oil rig is supported on the trailer by the pin or axle at A and the frame at B. If the rig has a weight of 115,000 lb and the center of gravity at G, determine the force F that must de developed along the hydraulic cylinder CD in order to start lifting the rig (slowly) off B toward the vertical. Also compute the horizontal and vertical components of reaction at the pin A.

Compute the horizontal and vertical components of force at pin B. The belt is subjected to a tension of T=100 N and passes over each of the three pulleys.

If the boom in the previous problem is to remain horizontal when the stone S is removed, what is x?

There is a ball and socket connection at A. At B there is a roller that prevents motion in the —z direction. Corner C is tied to D by a rope. The triangle is weightless. Determine the unknown force components acting at A, B, and C. Use a scalar analysis.

A Russell's traction is used for immobilizing femoral fractures C. If the lower leg has a weight of 8 lb, determine the weight W that must be suspended at D in order for the leg to be held in the position shown. Also, what is the tension force F in the femur and the distance  which locates the center of gravity G of the lower leg? Neglect the size of the pulley at B.

The crane provides a long-reach capacity by using the telescopic boom segment DE. The entire boom is supported by a pin at A and by the telescopic hydraulic cylinder BC, which can be considered as a two-force member. The rated load capacity of the crane is measured by a maximum force developed in the hydraulic cylinder. If this maximum force is developed when the boom supports a mass m = 6 Mg and its length is l = 40 and = 60°, determine the greatest mass that can be supported when the boom length is extended to l = 50 m and = 45°. Neglect the weight of the boom and the size of the pulley at E. Assume the crane does not overturn. Note: when = 60° BC is vertical; however, when = 45° this is not the case.

Determine the horizontal and vertical components of reaction at the pin A and the reaction at the roller support B required for equilibrium of the truss.

There is a ball and socket connection at A. At point B there is a connection that opposes motion in the x and z directions only. Determine the unknown force components at A and B. Use a scalar analysis.