The escalator that leads down into a subway station has a length of 24.5 m and a speed of 2.0 m/s relative to the ground. A student is coming out of the station by running in the wrong direction on this escalator. The local record time for this trick is 11 s. Relative to the escalator, what speed must the student exceed in order to beat the record?

Question

Patches

Physics

16 November, 12:55

The escalator that leads down into a subway station has a length of 24.5 m and a speed of 2.0 m/s relative to the ground. A student is coming out of the station by running in the wrong direction on this escalator. The local record time for this trick is 11 s. Relative to the escalator, what speed must the student exceed in order to beat the record?

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Answers (1)

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Marc Oconnell · Answer 1

Answer:any speed greater than 4.22 m/s

Explanation:

Given

Length of substation = 24.5 m

speed of escalator = 2 m/s

Time to cross the escalator is 11 s

let v be the speed of boy

Therefore minimum speed to match the record time is

24.5 = (v-2) 11

v-2=2.22

v=4.22 m/s

Therefore a speed greater than 4.22 m/s is required to beat the record