posted by Lor .
A 0.101 kg meter stick is supported at its 40 cm mark by a string attached to the ceiling. A 0.68 kg object hangs vertically from the 6.61 cm mark. A second mass is attached at another mark to keep it horizontal and in rotational equilibrium. If the tension in the string attached to the ceiling is 22.5 N, find the second mass. The acceleration due to gravity is 9.8 m/s^2.