A lamp of mass m hangs from a spring scale that is attached to the ceiling of an elevator.When the elevator is stopped at the fortieth floor,the scale reads mg.What does it read as the elevator slows down to stop at the forty-fifth floor?
A)more than mg
B)less than mg
C)mg
D)zero
E)One cannot tell without knowing how fast the elevator is stopping.

Question

Quizplus · Accepted Answer

The scale will read the weight of the lamp, which is mg, regardless of whether the elevator is moving up, down, or is stationary. The slowing down of the elevator does not affect the reading of the scale.

A Lamp of Mass M Hangs from a Spring Scale