NEET 2017 Physics Relative Motion MCQ Question
Preeti reached the metro station and found that the escalator was not working. She walked up the stationary escalator in time t₁. On other days, if she remains stationary on the moving escalator, then the escalator takes her up in time t₂. The time taken by her to walk up on the moving escalator will be:
t₁ + t₂/2
t₂ - t₁
t₁t₂/t₂ + t₁
t₁ - t₂
Correct Answer
Detailed Explanation
The effective speed when Preeti walks on the moving escalator is the sum of her walking speed and the escalator speed. The time taken is given by the harmonic mean: t₁t₂/(t₁ + t₂).
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