A train is running at a speed of 129 km/h on a straight railway track, and a small car on a parallel road is running at a speed of 60 km/h. How long (in seconds, rounded off to the nearest integer) will the train take to cross the car completely if the train is 943 m long and they are running in the same direction?
Ignore the length of the car as compared to the length of the train.
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 49
If the train is moving at a speed of 129 km/h and the car is moving at a speed of 60 km/h, then the net speed movement of the train beyond the car is = 129 - 60 = 69 km/h.
To cross the car completely, the train has to cover its whole length by to take over the car.
Thus the length of train = 943 m or 0.943 km
Thus, Time taken by train to cover this length = Distance/Speed
= 0.943/69
= 0.0136667 hours
To convert it into seconds, we will multiply it by 3600 (as 1 hours = 3600 seconds)
= (0.0136667)(3600)
= 49.20012 seconds
Thus, the train will take 49 seconds (rounded off figure) to cross the car.