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1. Oct 20, 2015

### PhysicsStudent1

1. The problem statement, all variables and given/known data
When a 45-kg person steps on a scale in an elevator, the scale reads a steady 480 N. Which of the following statements must be true? There could be more than one correct choice.
a) The elevator is accelerating upward at a constant rate
b) The elevator is moving downward at a constant rate
c) The elevator is moving upward at a constant rate
d) The elevator is accelerating downward at a constant rate
e) From the given information, we cannot tell if the elevator is moving up or down

2. Relevant equations
F = ma
Fg = mg
3. The attempt at a solution
From the equation, I know that the Fg is (45)(9.8) = 441.
I think the answer is a. But my textbook says that it is both A and E. Can someone help explain why? Thanks in advance :)

2. Oct 20, 2015

### Staff: Mentor

Hint: "moving up or down" refers to velocity, not acceleration. What's the difference?

3. Oct 20, 2015

### PhysicsStudent1

oh ok gotcha thank you :)