Question

A person who normally weighs 580 N is riding in an elevator that is moving upward, but slowing down at a steady rate. If this person is standing on a bathroom scale inside the elevator, what would the scale read

Answer 1

M au = Fs - M g au = upwards acceleration; Fs = scale reading

Fs = M (au + g) scalar quantities where g is positive downwards and au is positive upwards - Fs is the net force acting on the person

If the acceleration is zero Fs = M g and the scale reads the persons weight

If the elevator is decelerating then au is negative and the scale reading Fs = (g - au) M and the scale reading is less than the weight of the person