# Problems on Trains – Important Formulas

1. km/hr to m/s conversion: 2. m/s to km/hr conversion: 3. Formulas for finding Speed, Time and Distance

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

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

6. 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.

7. Suppose two trains or two objects’ bodies are moving in opposite directions at u m/s and v m/s, then their relative speed is = (u + v) m/s.

8. If two trains of length a metres and b metres are moving in opposite directions at u m/s and v m/s, then: 9. If two trains of length a meters and b meters are moving in the same direction at u m/s and v m/s, then: 10. 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: 