# What force does the scale display in Newtons?

1. Dec 9, 2008

### dreamgirl

Jasmine has a mass of 7 kg. He stands on a scale in an elevator that is accelerating downward at 4.9 m/sec ^2 . What force does the scale display in Newtons?

Thank you for your help!! :]

F = ma
i get 34.3

what is the unit i attach it to?

Last edited: Dec 9, 2008
2. Dec 9, 2008

### tiny-tim

Welcome to PF!

Hi dreamgirl! Welcome to PF!

(please use the homework forum in future )

Use good ol' Newton's second law … F = ma …

what is the acceleration? and what is the force(s)?

3. Dec 9, 2008

### dreamgirl

Thanks for the welcome!!! :]

another question:
when i get it, is the number automatically in Newtons?

i get 34.3

what is the unit i attach it to?

4. Dec 10, 2008

### tiny-tim

SI units

Hi dreamgirl!

Yes … so long as all your inputs are in SI units, the output will be in SI units also.

The inputs are kg and m and s, so the output will be in the SI unit of force, the newton (small n, btw, like watt and joule … it's only a capital N for the symbol, like W and J ).