by Guest » Wed Oct 05, 2005 2:58 am
Specific gravity is the relative density vs water. You also need to look up the absolute density of water. I think it is around 62 pounds/cubic foot, but I always do problems like this in metric, where it is very close to 1.000 kg/L (for most temperatures.)
At any rate, you need
volume * specific_gravity * absolute_density_of_water
depending on units of volume and water density, you may have to resolve (convert) some units too.