JEE Mains · Physics · STD 11 - 2. motion in straight line
Preeti reached the metro station and found that the escalator was not working. She walked up the stationary escalator in time \(t_1\) . On other days, if she remains stationary on the moving escalator, then the escalator takes her up in time \(t_2\). The time taken by her to walk up on the moving escalator will be
- A \(\frac{{{t_1}{t_2}}}{{{t_2} - {t_1}}}\)
- B \(\;\frac{{{t_1}{t_2}}}{{{t_2} + {t_1}}}\)
- C \({t_1} - {t_2}\)
- D \(\frac{{{t_1} + {t_2}}}{2}\)
Answer & Solution
Correct Answer
(B) \(\;\frac{{{t_1}{t_2}}}{{{t_2} + {t_1}}}\)
Step-by-step Solution
Detailed explanation
\begin{array}{l} Let\,{v_1}\,is\,the\,velocity\,of\,preeti\,on\,stationary\,escalator\,and\,\\ d\,is\,the\,{\rm{distance}}\,travelled\,bt\,her\\ \therefore \,{v_1} = \frac{d}{{{t_1}}}\\ Again\,let\,{v_2}\,is\,the\,velocity\,of\,escalator\,\\ \therefore \,{v_2} =…
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