posted by shan .
The uniform rod AB is suspended in air and its two ends are attached to supports by hinges.The rod has a weight of 15 lb and the spring is unstretched when θ = 0°. If θ = 30°, determine the stiffness k of the spring so that the rod is in equilibrium.
You need to describe the system better, since there is no figure. Where is the spring attached? In what direction does it pull or push? How is theta measured?