A train running at 60 km/h crosses a pole in 12 seconds. What is the length of the train?

Appeared in: AIIMS BHOPAL NO- 2018( Shift-2nd)

Explanation

The core task is to find the length of the train, which is the distance it travels while passing the pole.
First, convert the speed from km/h to m/s for unit consistency. Speed = 60 km/h × (5/18) = 50/3 m/s.
Next, apply the formula Distance = Speed × Time.
The distance covered to cross a pole is the train's own length.
Length = (50/3 m/s) × 12 seconds = 200 meters.

Option A: This is an incorrect result, likely due to a calculation error during the multiplication or division.
Option B: This result might be obtained if the speed conversion or the final multiplication is done incorrectly. For example, incorrectly calculating 60 * (5/18) * 12.
Option D: This is an incorrect result. It might arise from rounding the speed (50/3 m/s ≈ 16.67 m/s) incorrectly or another calculation mistake.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Calculation of Time, Speed, and Distance as background academic context rather than a clinical decision trigger.
This question tests fundamental quantitative aptitude and problem-solving skills.
The ability to ensure unit consistency (converting km/h to m/s) is a critical skill in many technical and scientific fields, including precise calculations in a clinical setting (e.g., drug dosage, IV drip rates).
What if the train was crossing a 100-meter-long platform instead of a pole? In that case, the total distance to be covered would be (Length of Train + 100) meters. The equation would be (200 + 100) = (50/3) * Time, and you would solve for Time.

How to Approach the Question

First, identify the given parameters: Speed = 60 km/h and Time = 12 seconds.
Recognize that the units are inconsistent (hours vs. seconds). Decide to convert the speed to meters per second (m/s) to match the time unit.
Recall or look up the conversion factor: 1 km/h = 5/18 m/s.
Apply the conversion: 60 × (5/18) = 50/3 m/s.
Understand the principle: When a train crosses a pole, the distance it travels is equal to its own length.
Use the formula: Distance = Speed × Time. Substitute the values: Length = (50/3) × 12.

Concept Tested & Keywords

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Practise the full AIIMS BHOPAL NO- 2018( Shift-2nd)

Attempt every question from this paper in a timed mock, then review the full solution for each one.