Question

Suppose a car is moving along a straight line $OQ$ as shown in the figure. It moves from $O$ to $Q$ in $15$ seconds and then goes to $P$ in $5$ seconds. The average speed of a car moving from $O$ to $Q$ & back to $P$ will be:

• A. $7.5$ m/s
• B. $12.5$ m/s
• C. $10$ m/s
• D. $1.66$ m/s

Answer 1

The correct option is B $12.5$ m/s

Average speed$=\frac{totaldistance}{totaltime}=\frac{OQ+QP}{15+5}=\frac{200+50}{20}=\frac{250}{20}$

$\Rightarrow v_{avg}=12.5$ m/s

So (B) is correct.