Rahul roy

Problem: Two trains of equal length L,travelling at speeds v1 and v2 miles per hour in opposite directions,take t seconds to cross each other .then L in feet is:

Solution:

Total distance required to cover by one train is 2L.

By considering one train at rest then speed of other train is v1+v2.

As speed=distance/time,

v1+v2=L/T

converting into feet we get

L = 11(v1+v2)T 15