Question

A person walks up a stalled 10 m long escalator in 94 s. When standing on the same escalator, now moving, the person is carried up in 60 s. How much time would it take that person to walk up the moving escalator?

Answer 1

V1 = S / t1 = speed up stalled escalator = 10/94 = .106 m/s

V2 = S / t2 = speed of escalator = 10 / 60 = .167 m/s

V = V1 + V2 combined speed

T = S / V = 1 / t1 + 1 / t2 = t1 * t2 / (t1 + t2)

T = 60 * 94 / (60 + 94) = 36.6 sec

Check: combined speed = .106 + .167 = .273 m/s

T = 10 / .273 = 36.6