Multiple choice

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

  1. 40 m $s^{-1}$
  2. 25 m $s^{-1}$
  3. 10 m $s^{-1}$
  4. 20 m $s^{-1}$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

To overtake the bus in 100 seconds over a distance of 1000 meters, the relative speed of the scooterist with respect to the bus must be 1000 / 100 = 10 m/s. Since the bus is moving at 10 m/s, the scooterist's speed must be 10 + 10 = 20 m/s.

AI explanation

Using the concept of relative speed, the scooterist must cover the initial 1 km gap plus the distance the bus travels in 100 seconds. The bus travels a distance of 10 m/s multiplied by 100 s, which equals 1000 m or 1 km, meaning the scooterist must cover a total distance of 2 km in 100 seconds. The required speed is 2000 m divided by 100 s, giving 20 m/s.

Keep practicing — related questions