Elevator Weight and Acceleration

[BMWPower06]

Homework Statement

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.

Homework Equations

I can't get luke's weight, i know i use F=MA, but when i plugged in the knowns i got Kg, and it wants N.

 

[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.

 

[BMWPower06]

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

 

[Delta]

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