An escalator joins one floor with another 10 m above. The escalator is 20 m long and moves along its length at `1.0 ms^(-1)`. (a) What power must its motor deliver if it is required to carry a maximum of 100 persons per minute of average mass 60 kg ? (b) If a man walks up the escalator in 10 s, how much work does the motor do on him ? (c) If this man turned around at the middle and walked down the escalatir so as to stay at the same floor, would the motor do work on him ?
[Hint : Apply work energy theorem]
