Ex/ What is the density of 40g of copper, with the volume of 10cm³?
D=m/v=40g/10cm=4g/cm³. I understand this is confusing, (Blogger gives me limited features. Yes, excuses, I know, I'm full of them) but all you really have to do is divide a given mass by a given volume.
Ex2/ BUT BUT BUT BUT BUT. WHAT IF WE DON'T HAVE THE MASS OR VOLUME?!!!!! Oh gosh, I'm starting to hyperventilate just by the thought of it. I'm getting frantic too. BUT don't fear! All you have to do is switch things around here and there. What if you wanted to find the volume given the density and mass?
Since the general formula for density is d=m/v , using simple algebra, in order to find volume, we know v=m/d. Therefore, now all you have to do is plug the numbers in. I'm sure you all have learnt this skill in Math 10.
When something is more dense than another object, that object will sink. If something is less dense than another object, the less denser object will float on top of another. Oil and water is an excellent example. The oil will always float on top of the water no matter what, since oil is less dense than water. Here is a cool picture. YAY!