A child with a mass of 39 kg stands on a spring scale inside an elevator. For each of the scenarios below, draw a force diagram of the forces acting on the child and calculate the reading of the scale in newtons.
(a) The elevator is at rest.
(b) The elevator is accelerating downward at 1 m/s2.
(c) The elevator is moving upward at a constant velocity of 9 m/s.
(d) The elevator is accelerating upward at 3 m/s2.