1. Time taken by a train x meters long in passing a signal post or a pole
or a standing man = Time taken by the train to cover x meters.
2. Time taken by a train x meters long in passing a stationary object of length y meters = Time taken by the train to cover (x + y) metres.
3. Suppose two trains or two bodies are moving in the same direction at u kmph and v kmph such that u > v, then their relative speed = (u - v) kmph.
4. If two trains of length x km and y km are moving in. the same direction at u kmph and )I kmph, where u > v, then time taken by faster train to cross the slower train ={ (X+Y) / (U-V) }hrs.
5. Suppose two trains or two bodies are moving in opposite directions at u kmph and v kmph. Then, their relative speed = (u + v) kmph.
6. If two trains of length x km and y km are moving in opposite directions at u kmph and v kmph, then: time taken by the trains to cross eachother
= (x + y)/ (u + v) hrs.
7. If two trains start at the same time from two points A and B towards each other and after crossing they take a and b hours in reaching B and A respectively.
