Question

Two trains travel towards each other at 54 km/h and 36 km/h. If they are 450 m apart, how long will they take to meet?

Solution

1. For opposite directions, relative speed = 54 + 36 = 90 km/h.
2. Convert 90 km/h to m/s: 90 x 5/18 = 25 m/s.
3. Time = distance / relative speed = 450/25 = 18 seconds.
4. Therefore, they meet after 18 seconds.