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AP EAMCET · PHYSICS · Motion In One Dimension

A person walks up a stalled escalator in 90 s . When standing on the same moving escalator he reached in 60 s . The time it would take him to walk up the moving escalator will be.

  1. A 36 s
  2. B 72 s
  3. C 18 s
  4. D 27 s
Verified Solution

Answer & Solution

Correct Answer

(A) 36 s

Step-by-step Solution

Detailed explanation

\(\begin{aligned} & t_1=\frac{1}{v_m}, t_2=\frac{1}{v_s} \\ & t_3=\frac{1}{v_m+v_s}=\frac{1}{\frac{1}{t_1}+\frac{1}{t_2}}=\frac{t_1 t_2}{t_1+t_2}=\frac{90 \times 60}{90+60}=36 \mathrm{~s}\end{aligned}\)