Problems on trains important formulas:
 km/hr to m/s conversion:
a km/hr = 

a x 
5 

m/s. 
18 

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.

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

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 (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)
General Questions:
CLICK ON THE OPTIONS THEN YOU GET THE ANSWER OF THAT QUESTION
1. 
A train running at the speed of 60 km/hr crosses a pole in 9 seconds. What is the length of the train?


A. 120 meters B.180 meters
C.324 meters D.150 meters
2. 
A train 125 m long passes a man, running at 5 km/hr in the same direction in which the train is going, in 10 seconds. The speed of the train is:

A. 
45 km/hr 
B. 
50 km/hr 
C. 
54 km/hr 
D. 
55 km/hr 

3. 
The length of the bridge, which a train 130 metres long and travelling at 45 km/hr can cross in 30 seconds, is:

A. 
200 m 
B. 
225 m 
C. 
245 m 
D. 
250 m 

4. 
Two trains running in opposite directions cross a man standing on the platform in 27 seconds and 17 seconds respectively and they cross each other in 23 seconds. The ratio of their speeds is:

A. 
1 : 3 
B. 
3 : 2 
C. 
3 : 4 
D. 
None of these 

5. 
A train passes a station platform in 36 seconds and a man standing on the platform in 20 seconds. If the speed of the train is 54 km/hr, what is the length of the platform?

A. 
120 m 
B. 
240 m 
C. 
300 m 
D. 
None of these 
