An escalator joins one floor with another one 8.20 m above. The escalator is 13.3 m long and moves along its length at 62.0 cm/s.
(a) What power must its motor deliver if it is required to carry a maximum of 100 persons per minute, of average mass 75.0 kg?
(b) An 83.5 kg man walks up the escalator in 9.5 seconds. How much work does the motor do on him?
(c) If this man turned around at the middle and walked down the escalator so as to stay at the same level in space, would the motor do work on him? If so, what power does it deliver for this purpose?
(d) Is there any (other?) way the man could walk along the escalator without consuming power from the motor?