Question

A particle moves in straight line with velocity $6\text{m/s}$ and $3\text{m/s}$ for time intervals which are in the ratio $1:2$. Find average velocity of the particle.

• A. $2\text{m/s}$
• B. $3\text{m/s}$
• C. $4\text{m/s}$
• D. $5\text{m/s}$

Answer 1

The correct option is C $4\text{m/s}$

Let the particle moves with $6\text{m/s}$ for the time interval $t$ and with $3\text{m/s}$ for time interval $2t$
So, total displacement of the particle is given by
$S_{total}=6\times t+3\times 2t=12t$
and, total time of motion is $T=t+2t=3t$
So, average velocity is given by
$v_{avg}=\frac{S_{total}}{T}=\frac{12t}{3t}=4\text{m/s}$