A 180-lb man supports himself, while standing in the middle of a 20-lb platform, by pulling on the ropes. Determine the force that the man's feet exert on the platform. The pulleys are frictionless, each weighs 10 lb, and the platform is of uniform density. A B D Ε -3A3A4 1

The center of gravity of the 850-N man is at G. If the man pulls on the rope with a 388-N force, determine the horizontal distance b between the man's feet and G.

Repeat Prob. 4.152 assuming that the 400-kN force is applied at O instead of L.

The center of gravity of the 3000-lb car is at G. The car is parked on an incline with the parking brake engaged, which locks the rear wheels. Find (a) the normal forces (perpendicular to the incline) acting under the front and rear pairs of wheels; and (b) the friction force (parallel to the incline) under the rear pair of wheels.

Two concrete blocks weighing 320 lb each form part of the retaining wall of a swimming pool. Will the blocks be in equilibrium when the pool is filled and the water exerts the line loading shown?

The cable is loaded by an 80-lb vertical force at C and a horizonal force P at B. Determine P.

The homogeneous 20-kg door is held in the horizontal plane by a thrust hinge at O, a hinge at A, and the vertical prop BC. Determine all forces acting on the door.

The spring clamp of Fig. block Fagainst the floor. The force in the spring is F = k(e – lo), where e is the present length of the spring, lo = 3 in. is the unstretched length of the spring, and k = 240 lb/ft is the spring constant. Determine all forces acting on mem- ber ÁBC of the spring clamp and the force exerted by the spring clamp on the block E. is used to hold the 8 in. D E 8 in. 6 in -6 in.- 6 in.

pls be as detailed as possible

50 m 40 m- 6- In the design of the robot to insert the small cylindrical part into a close-fitting circular hole, the robot arm must exert a 90-N force P on the part parallel to the axis of the hole as shown. Determine the components of the force which the part exerts on the robot along axes (a) parallel and perpendicular to the arm AB, and (b) parallel and perpendicular to the arm BC. Ans.(a) -77.9 N, 45 N; (b) 63.6N ,63.6N 15°. 45 -P 90 N 60