Two trains of equal length are running on parallel lines in the same direction at 46 km/hr and 36 km/hr. The faster train passes the slower train in 36 seconds. The length of each train is:

Step 1: Understand the given data

• Both trains are of equal length
• Speed of faster train = 46 km/hr
• Speed of slower train = 36 km/hr
• Time taken to overtake = 36 seconds

Step 2: Convert speeds to meters per second

Speed of faster train = 46 × (5 / 18) = 12.78 m/s
Speed of slower train = 36 × (5 / 18) = 10.00 m/s

Step 3: Find the relative speed (since both are moving in the same direction)

Relative speed = 12.78 - 10.00 = 2.78 m/s

Step 4: Total distance covered in overtaking

To overtake, the faster train must cover the length of both trains (since both are of equal length):

Let the length of each train be L meters.

Then total distance = 2L

Step 5: Use the formula Distance = Speed × Time

2L = 2.78 × 36
2L = 100.08
L = 50.04

Answer: 50 meters

The length of each train is 50 meters.

This is a classic problem in speed-time-distance where two objects move in the same direction. The relative speed is crucial here because the faster train is gaining on the slower one. We also consider the full length of both trains since complete overtaking involves clearing both ends.