Question

Two rings of same material are placed as shown in figure. Distance of centre of mass of the system from point $O$ is :-

• A. $\frac{5 R}{6}$
• B. $\frac{R}{4}$
• C. $3R$
• D. $2R$

Answer 1

Answer: (C)

$m_{1}=M,m_{2}=2M$
$x_{C M}=\frac{m_{1} x_{1} + m_{2} x_{2}}{ m_{1} + m_{2}}=\frac{M \times R + 2 M \times 4 R}{M + 2 M}$