Arithmatical - Problems on Trains

CATEGORY

Important Facts and Formulae
1. a km/hr = a x 5 m/s.
18
2. a m/s = a x 18 km/hr.
5
3.

Time taken by a train of length l metres to pass a pole or a standing man or a signal post is equal to the time taken by the train to cover l metres.

4.

Time taken by a train of length l metres to pass a stationary object of length b metres is the time taken by the train to cover (l + b) metres.
5.

Suppose two trains or two objects bodies are moving in the same direction at u m/s and v m/s, where u > v, then their relative speed is = (u - v) m/s.
6.

If two trains (or bodies) start at the same time from points A and B towards each other and after crossing they take a and b sec in reaching B and A respectively, then
  (A's speed) : (B's speed) = (√ b  : √ a)