# Thread: Volume using mass and density.

1. ## Volume using mass and density.

This is really easy, but im missing a step and I can't figure out what.

Question states an object $\displaystyle 1.35kg$, density is $\displaystyle 11.4g/cm^3$

What is its volume?

So I decided to attempt the question by converting the 1.35kg to 1350g

$\displaystyle V = M/D$

ANSWER A $\displaystyle 1350/114 = 118.42cm^3$

alternately, converting g/cm^3 to kg/m^3
$\displaystyle 11.4g/cm^3 = 11400kg/m^3$

ANSWER B $\displaystyle 1.34/11400 = 0.000188kg^3$

the problem arises when i try converting answer A to kg^3 and answer B to cm^3, they don't match up, anyone catch where my error is?

2. ## Re: Volume using mass and density... frustrated

Originally Posted by polskon
This is really easy, but im missing a step and I can't figure out what.

Question states an object $\displaystyle 1.35kg$, density is $\displaystyle 11.4g/cm^3$

What is its volume?

So I decided to attempt the question by converting the 1.35kg to 1350g

$\displaystyle V = M/D$

ANSWER A $\displaystyle 1350/114 = 118.42cm^3$

alternately, converting g/cm^3 to kg/m^3
$\displaystyle 11.4g/cm^3 = 11400kg/m^3$

ANSWER B $\displaystyle 1.34/11400 = 0.000188kg^3$

the problem arises when i try converting answer A to kg^3 and answer B to cm^3, they don't match up, anyone catch where my error is?
$\displaystyle kg^3$ ???

$\displaystyle 118.42 cm^3 \cdot \frac{1 \, m^3}{10^6 \, cm^3} = 0.000118 \, m^3$

3. ## Re: Volume using mass and density... frustrated

I am such a fool, thanks. Answers should be in CM^3 and M^3.

I should be converting CM^3 to M^3 and vice versa.

I feel like a tool, but thank you!

4. ## Re: Volume using mass and density... frustrated

Originally Posted by polskon
I feel like a tool, but thank you!
Don't...now you'll never repeat that slip, right?