Question

Two trains of lengths 180 m are moving on parallel tracks. If they move in the same direction then they cross each other in 15 s, and if they move in opposite directions then they cross in 7.5 seconds, then calculate their velocities. 

Answer 1

Total distance to be covered= 180+180=360m 

Let V₁, V₂ be velocities of trains It they move in same direction, relative 

velocity = V₁-V₂ 

Opposite direction, relative velocity = V₁+V₂