A uniform 240-g meter stick can be balanced by a 240-g weight placed at the 100-cm mark if the fulcrum is placed at the point marked:
A)75 cm
B)60 cm
C)50 cm
D)40 cm
E)80 cm

Question

Quizplus · Accepted Answer

The meter stick can be balanced at the 75 cm mark because the system is in equilibrium when the torques about the fulcrum are equal. The 240-g weight at the 100-cm mark creates a torque that is balanced by the uniform 240-g meter stick's mass distributed along its length, effectively acting as if its mass is concentrated at its center (50 cm from either end). Moving the fulcrum to 75 cm means the weight's torque (240g * 25cm) is balanced by the stick's torque, considering its center of mass is now 25 cm from the fulcrum on the other side.

A Uniform 240-G Meter Stick Can Be Balanced by a 240-G