A man stands on a scale while riding an elevator. The mass of the man is 84kg. What will the scale say if the elevator is descending at the same rate as gravity? What will the scale say if the elevator is ascending at a constant speed of 15m/s?

1 Answer
Oct 9, 2015

If the elevator descends at the same rate as gravity, ie #9,8m//s^2# down, then it is in free fall and the only force acting on it is the force of gravity and so the scale will read #0N#.

If the lift ascends (or descends) at a constant velocity, then there is no resultant force acting on it and so the scale will read the man's actual mass of 84 kg or his actual weight of 823,2 N.