﻿ Two trains 120 m and 80 m in length are running in opposite direction with velocities 42 km/hr and 30 km/hr. In what time they will complete cross each other?  from Physics Motion in A Plane Class 11 Manipur Board

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Two trains 120 m and 80 m in length are running in opposite direction with velocities 42 km/hr and 30 km/hr. In what time they will complete cross each other?

Relative velocity of one train w.r.t second,

= 42 - (-30)

= 72 km /hr

= 20 m/s

Total distance to be travelled = 120 + 80 = 200 m

Time taken  = 200/20 = 10 sec

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