A 5.0 m weightless strut, hinged to a wall, is used to support a 800-N block as shown. The horizontal and vertical components of the force of the hinge on the strut are: A) F_H= 800 N, F_Y = 800 N B) F_H= 600 N, F_Y = 800 N C) F_H= 800 N, F_Y = 600 N D) F_H= 1200 N, F_Y = 800 N E) F_H= 0 , F_Y = 800 N

Question

Quizplus · Accepted Answer

Since the strut is weightless, the only forces acting on it must be at the two ends. The hinge exerts a force on the strut, as does the block. Since the strut is in equilibrium, the net force on it must be zero, and the net torque about any point (in particular, the hinge) must be zero as well. Taking moments about the hinge: 800N * 5m - F_Y * 5m = 0 This yields F_Y = 600N. The horizontal component of the force of the hinge on the strut must balance the horizontal force of the block (which is zero since it's not moving), so F_H = 0. Thus, the answer is B: F_H= 600 N, F_Y = 800 N.

A 50 M Weightless Strut, Hinged to a Wall, Is Used