The load carrying capacity of the frame of Prob. 4.11 can be increased by placing a counterweight Q at point D as shown. The resultant moment about point A due to the cable forces and Q is not to exceed 20 kN·m.
(a) Determine the largest value of counterweight Q.
(b) With the value of Q determined in Part (a), determine the largest weight W that may be supported and the corresponding value of a.
