A person walks up a stationary escalator in $t_{1}$ second. If he remains stationary on the escalator, then it can take him up in $t_{2}$ second. If the length of the escalator is L, then how much time would it take him to walk up the moving escalator?

$\frac{t_{1} t_{2}}{t_{1} - t_{2}}$

No worries! We‘ve got your back. Try BYJU‘S free classes today!

$\frac{t_{1} t_{2}}{t_{1} + t_{2}}$

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

$\frac{t_{1} + t_{2}}{t_{1} t_{2}}$

No worries! We‘ve got your back. Try BYJU‘S free classes today!

$\frac{t_{1} - t_{2}}{t_{1} t_{2}}$

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Open in App

Solution

The correct option is B
$\frac{t_{1} t_{2}}{t_{1} + t_{2}}$

Speed of man w.r.t. the ground $v_{m} = v_{m c} + v_{c} \Rightarrow v_{m} = \frac{L}{t_{1}} + \frac{L}{t_{2}} = L [\frac{1}{t_{1}} + \frac{1}{t_{2}}] + L [\frac{t_{1} + t_{2}}{t_{1} t_{2}}]$

$\Rightarrow t = \frac{L}{v_{m}} = [\frac{t_{1} t_{2}}{t_{1} + t_{2}}]$ the time taken by the man to walk up the moving escalator.

Suggest Corrections

Similar questions

A person walks up a stationary escalator in $t_{1}$ second. If he remains stationary on the escalator, then it can take him up in $t_{2}$ second. If the length of the escalator is L, then how much time would it take him to walk up the moving escalator?