# Homework Help: Weight Density and Mass Density

1. Dec 2, 2008

### GreenEyedGal3

1. The problem statement, all variables and given/known data
I measured the weight(in Newtons), mass(in Kilograms), and volume(in cubic meters) of some objects. Then I tried to calculate the mass density and the weight density of the objects.

2. Relevant equations
Weight Density = weight/volume

Mass Density = mass/volume

ex. weight density of object one ... 2.00 N / 2.55x10-5 m3 = 78431 ??
mass density of object one ... .204kg / 2.55x10-5 m3 = 8000 ??
3. The attempt at a solution

I have found my numeric answers but i do not know what units the weight density and mass density are measured in. Would the weight density be measured in newtons/ cubic meters and the mass density in kg/ cubic meters?

2. Dec 2, 2008

### Hootenanny

Staff Emeritus
Yes, those would be the unit's to use. However, you may want to re-check your calculations.

3. Dec 2, 2008

### GreenEyedGal3

I keep getting the same thing on my calculations. Should i round to the right number of significant digits or should i change my calculator from degrees to radians?

4. Dec 2, 2008

### D H

Staff Emeritus
The calculations look fine. Are you hinting about the numbers? It looks to me like the OP was using stainless steel.

What makes you think that this will make any difference?

5. Dec 2, 2008

### Hootenanny

Staff Emeritus
I was referring to the disparity between the weight of the object and the given mass multiplied by g:

(0.204*9.81)/(2.55*10-5) = 78480