Question

Suppose the mass of the stick is 200 g, and a single 500-g mass is to play "solitary seesaw" at the 0-cm mark. Where should the fulcrum be located?

Answer 1

Assume L for length of stick.

Put the fulcrum at x from the 500-g mass.

The centre of gravity of the stick is at the centre, L/2, where the mass is assumed to concentrate.

Take moments about the fulcrum:
500*x=200*(L/2-x)
Solve for x in terms of L:
x=L/7