Maximum speed!!!!!!!!!!!!!!!!!?

Question

If the maximum acceleration that is tolerable for passengers in a subway train is 1.31 m/s2, and subway stations are located 626 m apart, what is the maximum speed a subway train can attain between stations?

What is the travel time between stations?

If the subway train stops for 15 s at each station, what is the maximum average speed of a subway train, from one start-up to the next?

Answer 1

Assuming that that acceleration maximum is in either direction, ie, for braking as well as accelerating.

The train has to spend half the time and distance accelerating at 1.31 m/s2, and the second half deccelerating at the same rate.

d = ½at²

313 = ½(1.31)t²

t² = 478

t = 22 seconds. total travel time is 44 seconds.

2) total distance = 626 m

total time = 44+15 = 59s

Av V = 626/59 = 10.6 m/s

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