Question 67174
Well, to solve this one, I just used a calculator with the cube root function, because the volume of a cube is equal to length times width times height ({{{length*width*height}}}, and since all sides are the same, you'd get cube root.

The answer would be {{{8}}}. 
({{{8^3=512}}})

If you're interested in finding cube roots by hand, I suggest <a href="http://www.nist.gov/dads/HTML/cubeRoot.html">this page</a>.

I hope that helps you out. :)
-Zoop