Elevator Weight and Acceleration

AI Thread Summary
The discussion revolves around calculating the acceleration of an elevator and Luke's weight while standing on a scale. The scale reads 0.968 kN when the elevator accelerates upward, and 1.215 kN when Luke lifts an 18.6 kg box. The calculated acceleration of the elevator is 3.48 m/s² upward. Users are confused about calculating Luke's weight, mistakenly converting values and mixing mass with weight. The correct approach involves using the net force equation, factoring in both gravitational and elevator acceleration to find accurate results.
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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.
 
Last edited:
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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.
 
Ok, i did (968N/3.48) x (9.8)= 2725.97N yet it says I am wrong, any ideas?
 
The 968N comes from a combination of gravitational acceleration and the acceleration of the elevator.
 

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