Question

For equilibrium of the system, value of mass $m$ should be

• A. 9 kg
• B. 15 kg
• C. 21 kg
• D. 1 kg

Answer 1

Answer: (B)

Net torque $=0$ for equilibrium
$12l=m\left(\frac{l}{2}\right)+3\left(\frac{3l}{2}\right)$
$12l-4.5l=\frac{ml}{2}$
$7.5l=\frac{ml}{2}$
$m=15kg$