Question

A bus is moving with a velocity $10m{s}^{-1}$ on a straight road. A scooterist wishes to over take the bus in $100s$. If the bus is at a distance of $1km$ from the scooterist, with what velocity should be scooterist chase the bus?

• A. $50m{s}^{-1}$
• B. $40m{s}^{-1}$
• C. $30m{s}^{-1}$
• D. $20m{s}^{-1}$

Answer 1

The correct option is D $20m{s}^{-1}$

$t=100s,s=1000m,v=10m/s$ (but this is the relative speed with respect to the bus)
let,$V_s=$actual speed of scooter ,$V_b=$actual speed of bus
relative velocity with respect to bus, v$=V_s-V_b$
since,both scooter and the bus moving in same direction $10=V_s-10;so,V_s=20m/s$
so,,the scooterist, should be chase the bus with the velocity of $20m{s}^{-1}$.
hence,option D is correct.