Question

A body moves with velocity $v$, $2v$ and $3v$ in the first,second and third time intervals with one-third distance of the path is travelled in each time interval. Its average velocity is

• A. $\frac{36}{11}v$
• B. $\frac{18}{11}v$
• C. $\frac{6}{11}v$
• D. $\frac{12}{11}v$

Answer 1

The correct option is B $\frac{18}{11}v$

We know that $\frac{totaldisplacement}{totaltime}=$Avg velocity.

total distance $=3x$
total time $=\frac{x}{v}+\frac{x}{2v}+\frac{x}{3v}$

$\Rightarrow \frac{3x}{\frac{x}{v}+\frac{x}{2v}+\frac{x}{3v}}=\frac{18}{11}v.$