Solve the below problem:
Q: A slender rod AB of weight W is attached to blocks A and B which move freely in the guides shown. The constant of the spring is k, and the spring is unstretched d when θ = 0.
(a) Neglecting the mass of the blocks, derive an equation in W, k, l, and B which must be satisfied when the rod is in equilibrium.
(b) Determine the value of θ when W = 4 lb, l = 30in. and k = 1.8 lb/ft.