A 2.00 kg block hangs from a spring balance calibrated in Newtons that is attached to the ceiling of an elevator.

(a) What does the balance read when the elevator is ascending with a constant speed of 29 m/s?

(b) What does the balance read when the elevator is descending with a constant speed of 25 m/s?

(c) What does the balance read when the elevator is ascending at 39 m/s and gaining speed at a rate of 10 m/s2?

(d) Suppose that from t = 0 to t = 4.9 s, the elevator ascends at a constant speed of 10 m/s. Its speed is then steadily reduced to zero during the next 3.2 s, so that it is at rest at t = 8.1 s. Describe the reading of the scale during the interval 0 < t < 8.1 s.