Question

A homogenous rod of length 1 m is pivoted at the sign of 40 cm. A block of 10 g is suspended at sign of 10 cm. If the rod is in equilibrium then find its mass.

Answer 1

In equation

∑τ = 0

∴ Anticlockwise torque = Clockwise torque

or 10g x 30 = Mg x 10

or M = \(\frac{10\times30}{10} = 30g\)

or M = 30 g

Based on Moment of Inertia, Rotational Energy and Conservation Laws