# Elevator Weight and Acceleration

1. Jun 4, 2007

### BMWPower06

1. The problem statement, all variables and given/known data
Luke stands on a scale in an elevator which has a constant acceleration upward. The scale reads 0.968 kN. When Luke picks up a box of mass 18.6 kg, the scale reads 1.215 kN. (The acceleration remains the same.) Calculate the acceleration of the elevator (enter first). Is it up or down?

my answer: 3.48 m/s^2 up

Calculate Luke's weight.
2. Relevant equations
I cant get luke's weight, i know i use F=MA, but when i plugged in the knowns i got Kg, and it wants N.

Last edited: Jun 4, 2007
2. Jun 4, 2007

### Delta

It's because the question is asking for his weight not his mass. If you can work out his "mass", your can work out his weight.

3. Jun 4, 2007

### BMWPower06

Ok, i did (968N/3.48) x (9.8)= 2725.97N yet it says im wrong, any ideas?

4. Jun 5, 2007

### Delta

The 968N comes from a combination of gravitational acceleration and the acceleration of the elevator.