Question

Two point masses $m$ and $M$ are separated by a distance $L$. The distance of the center of mass of the system from $m$ is :

• A. $L\left(m/M\right)$
• B. $L\left(M/m\right)$
• C. $L\left(\frac{M}{m+M}\right)$
• D. $L\left(\frac{m}{m+M}\right)$

Answer 1

Answer: (C)

$L\left(\frac{M}{m+M}\right)$

Taking the position of $m$ as origin and the line joining the $m$ and $M$ as the x axis we get the

position of $m$ as $x_1=0$ and the position of the $M$ will be $x_2=L$

So the position of the center of mass will be $x=\frac{m\times 0+M\times L}{m+M}=\frac{M}{m+M}L$