A 72 kg man stands on a spring scale in an elevator. Starting
from rest, the elevator ascends, attaining its maximum speed of 1.2
m/s in 0.73 s. It travels with this constant speed for 5.0 s,
undergoes a uniform negative acceleration for 1.2 s, and comes to
rest. What does the spring scale register in each of the following
time intervals?
(a) before the elevator starts to move
_____ N
(b) during the first 0.73 s
_____N
(c) while...