Question

A 200g mass is placed on the meter stick 20cm from the fulcrum. A 170g mass is used to balance the system. How far will it have to be located from the fulcrum to keep the system in balance?

Answer 1

The equation of equilibrium of moments gives

$$m_1gl_1=m_2gl_2$$

$$l_2=m_1/m_2l_1=200/170*20=23.5\:\rm cm$$