Multiple choice

Two trains, each $50m$ long, are travelling in opposite directions with velocity $10m/s$ and $15m/s$. The time of crossing is-

  1. $2s$
  2. $4s$
  3. $2\sqrt {3}s$
  4. $4\sqrt {3}s$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

When two trains travel in opposite directions, their relative speed is the sum of their individual speeds: 10 + 15 = 25 m/s. The total distance to cover is the sum of their lengths: 50 + 50 = 100 m. Time = Distance / Speed = 100 / 25 = 4 seconds.

AI explanation

The relative speed of the two trains moving in opposite directions is the sum of their speeds, giving 10 m/s + 15 m/s = 25 m/s. The total distance they must cover to completely cross each other is the sum of their lengths, which is 50 m + 50 m = 100 m. Using the formula time equals distance divided by relative speed, we calculate 100 m divided by 25 m/s, resulting in 4 s.

Keep practicing — related questions