Question

Two spheres $A$ and $B$ of masses $m$ and $2m$ and radii $2R$ and $R$ respectively are placed in contact as shown. The COM of the system lies

• A. Inside A
• B. Inside B
• C. At the point of contact
• D. None of these

Answer 1

The correct option is C At the point of contact

Distance of COM from centre of sphere A,
$r_1=\frac{m_{B}r}{m_A+m_B}=\frac{2m\times 3R}{m+2m}=2R$
ie COM is at the point of contact