Question

A uniform meter stick is supported by a knife edge at the 50.00 cm mark and has masses od 0.20 kg and 0.50 kg hanging from the 20.00 cm and 85.00 cm marks respectively. Where should a third mass of 0.30 kg be hung to keep the stick balanced?

Answer 1

The torque about the knife edge would be zero for equilibrium due to the weights of the three masses. Use this to find the required position as shown below