39. A 19-foot beam 10 inches wide and 20 inches high supports 1500 lb / ft on two supports 14 feet apart. The right end of the beam extends 2 feet past the support. What is the shearing stress midway between supports?

 A. 1.0 psi

 B. 10 psi

 C. 67 psi

 D. 2.0 psi

 

 

S1. A rigid body rotates about a fixed axis x, with the angular rotation rate, , the kinetic energy of the body is where is the moment of the inertia of the body about the axis, x.

 

S2. A wheel subject to an external force moves along a horizontal rough surface, the friction force from ground on the wheel is N . is the static friction coefficient between the wheel and rough surface, and N is the normal supporting force from ground surface to the wheel.