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?

Difficulty: Easy

Correct Answer: 18 seconds

Explanation:

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

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