Q96 / 197 · NEET 2009 (Mains) · Physics
A bus is moving with a speed of $10 \mathrm{~ms}^{-1}$ on a straight road. A scooterist wishes to overtake the bus in $100 \mathrm{~s}$. If the bus is at a distance of $1 \mathrm{~km}$ from the scooterist, with what speed should the scooterist chase the bus ?
- A$10 \mathrm{~ms}^{-1}$
- Correct answerB$20 \mathrm{~ms}^{-1}$
- C$40 \mathrm{~ms}^{-1}$
- D$25 \mathrm{~ms}^{-1}$
Solution
$$
\begin{aligned}
\mathrm{S}_{\mathrm{r}} & =\mathrm{v}_{\mathrm{r}} \mathrm{t} \\
1000 & =(\mathrm{v}-10) \times 100 \\
\mathrm{v} & =20 \mathrm{~m} / \mathrm{s}
\end{aligned}
$$
Hence, the correct answer is option: 'B'.