Question

Two particles of mass 1 kg and 2 kg are located at x = 0 and x = 3 m. Find the position of their center of mass.

• A. 4 m
• B. 2 m
• C. 6 m
• D. 8 m

Answer 1

Answer: (B)

2 m

Since, both the particles lies on x - axis, the COM will also lie on x - axis. Let the COM islocated at x$=$ x, then
$r_1$ $=$ distance of COM from the particle of mass 1 kg$=$ x
and $r_2$ $=$ distance of COM from the particle of mass 2 Kg $=$ (3 - x)
Using
$\frac{r_1}{r_2}=\frac{m_2}{m_1}$
or $\frac{x}{3-x}=\frac{2}{1}$
or $x=2m$
Thus, the COM of the two particles is located at x $=$ 2 m.