Multiple choice

A 150 m long train moving at the speed of 45 m/sec. crosses another 180 m long train coming from opposite direction in 2.5 seconds. What is the speed of second train?

  1. 40 m/sec

  2. 42 m/sec

  3. 44 m/sec

  4. 46 m/sec

  5. 87 m/sec

Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Total distance = 150 + 180 = 330 m. Time = 2.5 seconds. Relative speed = Distance/Time = 330/2.5 = 132 m/s. Since trains are moving in opposite directions, relative speed = Speed1 + Speed2. So 132 = 45 + Speed2, giving Speed2 = 87 m/s.