Question

Position of two particles are given by $x_1=2t$ and $x_2=2+3t$. The velocity of centre of mass at $t=2\text{s}$ is $2\text{m/s}$. Velocity of centre of mass at $t=4\text{s}$ will be

• A. $2\text{m/s}$
• B. $4\text{m/s}$
• C. $1\text{m/s}$
• D. zero

Answer 1

The correct option is A $2\text{m/s}$

Since acceleration of the given particles are $a_1=\frac{d^2{x}_1}{d{t}^2}=0,a_2=\frac{d^2{x}_2}{d{t}^2}=0$
$\therefore$ Velocity of centre of mass remains constant
$\therefore$ (a).