PROBLEMAS DE EQUILIBRIO DEL CUERPO RIGIDO

4.26 Para el marco y las cargas mostradas en la figura, determine las reacciones en A y E cuando a) a=2” y b) a= 7.5” RESPUESTAS:

a). RA=271.lb RE=3.57Lb

b). RA=26.6Lb. RE=21Lb.

4.84 A slender rod of length L is attached to collars that can slide freely along the guides shown. Knowing that the rod is in equilibrium, derive an expression for the angle θ in terms of the angle β.

4.85 An 8-kg slender rod of length L is attached to collars that can slide freely along the guides shown. Knowing that the rod is in equilibrium and that β=30°, determine (a) the angle θ that the rod forms with the vertical, (b) the reactions at A and B. RESPUESTAS. 4.84 tanθ= 2 tanβ . 4.85 (a) θ=49.1°. (b) RA= 45.3 N; RB= 90.6 N

4.89 A slender rod of length L and weight W is attached to a collar at A and is fitted with a small wheel at B. Knowing that the wheel rolls freely along a cylindrical surface of radius R, and neglecting friction, derive an equation in θ, L, and R that must be satisfied when the rod is in equilibrium. 4.90 Knowing that for the rod of Prob. 4.89, L= 15 in., R=20 in., and W=10 lb, determine (a) the angle θ corresponding to equilibrium, (b) the reactions at A and B. 4.90 (a) θ=59.4°. (b) RA= 8.45 lb y; RB=13.09 lb