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

Relative velocity of one train w.r.to second is,Â

= 42 - (-30)

= 72 km/hr = 20 m/s

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

Time taken, t =Â Â

In 10 sec, the two trains will completely cross each other.Â

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