Problems on Trains – Time to pass an electric pole: A 250 m long train runs at 50 km/h. In how many seconds will it pass an electric pole?

Introduction / Context:
Passing a pole requires the train to cover its own length at its speed. Convert km/h to m/s, then divide length by speed to obtain time in seconds.

Given Data / Assumptions:

• L_train = 250 m.
• Speed = 50 km/h.

Concept / Approach:
Speed (m/s) = 50 * (1000/3600) = 13.888… m/s. Time = distance / speed.

Step-by-Step Solution:
Time = 250 / 13.888… ≈ 18 s.

Verification / Alternative check:
Check: 18 s * 13.888… ≈ 250 m, confirming the calculation.

Why Other Options Are Wrong:
30, 72, 60, 20 s do not equal L/v with correct conversion.

Common Pitfalls:
Using 50/3.6 ≈ 13.89 incorrectly rounded but the conclusion remains ≈ 18 s.

Final Answer:
18 seconds