## Trains

The Train Problems are a little different from regular object motion problems. This is due to the finite size of the trains. Many standard train issues arise as a result of the length of the trains.

• If two trains of lengths P and Q move in opposite directions at V1 m/s and V2 m/s, then the time taken by the trains to cross each other can be calculated by Time Taken = (P + Q) / (V1 + V2)
• If two trains of different lengths P and Q move in the same direction at V1 m/s and V2 m/s, then the time taken by the trains to cross each other is calculated by Time Taken = (P + Q) / (V1 – V2)

Formula to convert Km/hr into m/s:

• 1km is equal to 1000 meters
• 1 hour is equal to 3600 seconds
• 1Km/hr is equal to meter/sec or m/s

Formula to convert m/s to km/hr

• 1 meter is equal to 1/1000 km
• 1 sec is equal to 1/3600 hours
• 1 m/s is equal to

### Problems on Trains

1. A 250 m long train runs at a speed of 70 km / h. What long does it take to cross some stationary object at the railway station?

• A. 20 sec
• B. 17.23 sec
• C. 12.86 sec
• D. 9.5 sec

2. A train running at 50 km / h in the same direction as a train in 15 sec passes a man walking on the platform at 7 km / h. If this train takes 30 seconds to traverse the platform, then find train length (L1) and platform length (L2)?

• A. L1 =179.1 m, L2 = 237.3 m
• B. L1 = 150.5 m, L2 = 300 m
• C.  L1 = 237.3 m, L2 = 179.1 m
• D. L1 = 300 m, L2 = 150.5 m

Answer: Option A (L1 =179.1 m, L2 = 237.3 m)

3. A boy runs at a speed of 20 km / h opposite to that of the train. When the relative speed is 50 km / h between the train and the boy running in the opposite direction. What is the train’s length if it takes 20 seconds to traverse the boy when he’s in rest?

• A. 159.1 m
• B. 160.23 m
• C. 166.6 m
• D. 154.12 m

4. Two trains depart simultaneously from stations A and B and begin to travel towards each other. A runs at 120 km / h while B is 20 km / h slower than A. They meet at one stage, but by then, one train has already traveled more than 40 km of distance than the other. How distant are the two stations?

• A. 180 km
• B. 220 kms
• C. 260 kms
• D. 440 kms

5. A train, 400 m long, runs at 72 Kmph. How long will it take for the electric pole to cross?

• A. 15 sec
• B. 20 sec
• C. 19 sec
• D. 21 sec

6. A 110-meter long train operates at a speed of 60 kmph. At what time will a man running at six kmph in the opposite direction to the one the train is going in the pass?

• A. 10
• B. 8
• C. 4
• D. 6

7. If a train speed is 20 m / sec, find the train speed in Kmph

• A. 84 kmph
• B. 72 kmph
• C. 68 kmph
• D. 55 kmph

8. A man ‘s current speed is 15 km / h, and the current speed is 2.5 km / h. The speed of man against the current is

• A. 9.5 km/hr
• B. 10 km/hr
• C. 10.5 km/hr
• D. 11 km/hr

9. A 200 m long train travels at a speed of 50 km per hour. Find the Time it took to pass a tree near the railway track

• A. 14 2/5 seconds
• B. 15 seconds
• C. 16 1/2 seconds
• D. 17 seconds

Answer: Option A (14 2/5 seconds)

10. Two trains run at the same speed, in opposite directions. Each train’s length is 120 meters. If they cross one another in 12 seconds, each train ‘s speed (in km/hr) is

• A. 42
• B. 36
• C. 28
• D. 20

## Quote of the day!

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