The experiment is useful for estimating the weight of a man's legs. When the man is lying flat on a flat board with his legs flat to the board, the board is of length L between points A and B, a scale at point B on the right side reads S1.At point A on the left side of the board lies on a roller and is level between points A and B.

Also, the man when lying down on the board his head is towards point A and the legs towards point B.

By estimation it is determined that the center of gravity of the legs is at G, just above the knee area. When his legs are brought to a vertical position, the center of gravity is diplaced horizontally to the left a distance of d, which gives a new scale reading of S2.

Please answer the question above.

The answer is W = (L(S1-S2))/d ; please show how this answer was derivedby using the equations of equilibrium:

Sum of the forces in the X-direction = 0

Sum of the forces in the Y direction = 0

Sum of the moments about a point = 0

Ignore the weight of the board and possibly sum the moments about point A.

Please show all steps to show this derivation, Thanks