Q. A scooterist sees a bus 1 km ahead of him moving with a velocity of $10\ {ms}^{- 1}.$ With what speed the scooterist should move so as to overtake the bus in 100 s?
A) $10\ {ms}^{- 1}$
B) $15\ {ms}^{- 1}$
C) $20\ {ms}^{- 1}$
D) $17\ {ms}^{- 1}$
Explanation
(c) Distance covered by bus in 100 s
$\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ = 100 \times 10 = 1000\ m$
Distance to be covered by scooterist
$\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ = 1000 + 1000 = 2000\ m$
$\therefore Speed\ of\ scooterist = \frac{2000}{100} = 20\ {ms}^{- 1}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.