A 55.0 kg girl weighs herself by standing on a scale in an elevator.
a) What is the force exerted by the scale when the elevator is descending at a constant speed of 10 m/s?
b) What is the force exerted by the scale if the elevator is accelerating downward with an acceleration of 2.6 m/s2
c) If the elevator's descending speed is measured at 10 m/s at a given point, but its speed is decreasing by 2.6 m/s2, what is the force exerted by the scale?