A boy reaches the airport and finds that the escalator is not working. He walks up the stationary escalator in time t1. If he remains stationary on a moving escalator then the escalator takes him up in time t2. The time taken by him to walk up on the moving escalator will be :
Solution
L = Length of escalator<br><br>${V_{b/esc}} = {L \over {{t_1}}}$<br><br>When only escalator is moving.<br><br>${V_{esc}} = {L \over {{t_2}}}$<br><br>when both are moving<br><br>${V_{b/g}} = {V_{b/esc}} + {V_{esc}}$<br><br>$${V_{b/g}} = {L \over {{t_1}}} + {L \over {{t_2}}} \Rightarrow \left[ {t = {L \over {{V_{b/g}}}} = {{{t_1}{t_2}} \over {{t_1} + {t_2}}}} \right]$$
About this question
Subject: Physics · Chapter: Kinematics · Topic: Motion in a Straight Line
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