[nate2612]

I just started a course and when we covered this I wasn't in but I'm having a problem with this question.

Gold has a density of 19.3 grams per cc. if a gold nugget has a mass of 45.6 kg, what is its volume.

Can someone please explain how to get the answer

[DevaDevil]

assume the nugget is solid gold

you have the mass of the nugget
and the mass of gold per unit volume

should be easy to calculate, no?
( Mass of nugget = volume of nugget * density )

[nate2612]

Thanks thats what i thought but i had to make sure.

[Custos]

If ever you're not sure whether to multiple by the density or divide or whatever, look at the units and that will help you figure it out. Density is grams/cc, mass is grams and volume is cc. Make sure the units cancel themselves out to give the correct final unit and you will always get it the right way around. Same for working with moles, ml and molarity, or moles grams and molecular weights (grams/mole), and so on.

[Borek]

The most general approach is to use pretty simple algebra. Start with the density definition:

d = m/V

d for density, m for mass, V for volume. Now, you need mass - so you solve for mass:

m = d*V

You need volume, you solve for volume:

V = m/d

This approach works also in othe situations, like concentration calculations, speed-time-distance and so on. Note that the final formula can be checked with units as Custos signalled.