Apparent Weight Elevator Speed

1. Oct 5, 2008

shimizua

1. The problem statement, all variables and given/known data
Referring to the problem above, if the elevator's descending speed is measured at 10 m/s at a given point, but its speed is decreasing by 2.5 m/s2, what is her apparent weight?.
A 58.0 kg girl weighs herself by standing on a scale in an elevator. What is her apparent weight when the elevator is descending at a constant speed of 10 m/s?

2. Relevant equations
So i was able to find the answer to the first question which was 568N and found it by doing her mass times the gravity. but i have no i idea of how to do it when the speed it decreasing.

3. The attempt at a solution
i tried doing her mass times her acceleration which was 10m/s and that was wrong and so i then tried doing her mass time her deceleration of 2.5m/s/s and that was wrong as well. if you could just help with an equation that should be good enough. thanks

2. Oct 6, 2008

Kurdt

Staff Emeritus
Her apparent weight will be the weight due to gravity plus the force exerted on her by the lift.

Last edited: Oct 6, 2008
3. Oct 6, 2008

shimizua

ok so i would use my initial number of 568N and add that to what? her mass times the deceleration?
cool so i put that in and it does work, thanks man

4. Oct 6, 2008

HallsofIvy

Staff Emeritus
Yes, force = mass times acceleration. If the elevator is accelerating upward, then you would feel g+ mass * acceleration. If the elevator is accelerating downward, then you would feel g- mass*acceleration.