Load on beam:

A beam AB as shown in the figure given below is hinged at A and supported at B by a vertical cord that passes over two frictionless pulleys C and D. If pulley D carries vertical load Q, find out the position x of the load P if beam is to remain in equilibrium in horizontal position.

Consider the free body diagram of block Q, from the given figure,

2T = Q, T = Q/2

Tension in the rope = Q/2

Now consider F.B.D. of beam as shown in the figure, Here two forces are acting force 'P' at a distance 'X' from the point 'A' and T = Q/2 at a distance 'l' from point 'A'

By taking moment about point 'A', i.e. ΣM_A  = 0

P X x = Q/2 X l

X = QL/2P                                                                .......ANS