Does anyone know a good website or other source for practicing conversions and really just units in general? I'm having trouble with them, I'll give you an example problem I did to illustrate my problem... What is the pressure at a depth of 5 meters in alcohol? (The specific gravity of alcohol is .8) Pressure in water = weight density*depth Sg=mass density/ mass density of water -> .8 = mass density/ 1 = .8g/ccm (cubic centimeter) weight= mass*9.8 (force of gravity on Earth.) = .8*9.8=7.84 Newtons depth= 5 meters Pressure= 7.84N*5 meters = 39.2N/m The book answers are Mass density of Alcohol= 800 kilograms per cubit meter Weight density of Alcohol= 7840 Newtons per cubic meter Pressure at 5 meters deep in alcohol= 39,200 Newtons per square meter= 3.92 Netwons per square centimeter. What was the correct way of doing that problem? I know I did the math right, it's the units that are troubling me.