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. ΣMA = 0
P X x = Q/2 X l
X = QL/2P .......ANS