- महत्वपूर्ण लेख
- सामान्य सवाल
- किमी /घंटा से मी / सेकेंड में परिवर्तन :
a km/hr = 
a x 5 
m/s. 18 - मी / सेकेंड से किमी /घंटा परिवर्तन :
a m/s = a x 18 km/hr. 5 - चाल , समय और दुरी जानने के नियम
- Time taken by a train of length L metres to pass a pole or standing man or a signal post is equal to the time taken by the train to cover L metres.
- Time taken by a train of length L metres to pass a stationery object of length B metres is the time taken by the train to cover (L + B) metres.
- 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.
- 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.
- If two trains of length a metres and b metres are moving in opposite directions at u m/s and v m/s, then:
The time taken by the trains to cross each other = (a + b) sec. (u + v) - If two trains of length a metres and b metres are moving in the same direction at u m/s and v m/s, then:
The time taken by the faster train to cross the slower train = (a + b) sec. (u - v) - 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^1/2 : a^1/2)