1. The problem statement, all variables and given/known data A sample of an unkown material weighs 200 N in air and 150 N when immersed in water. What is the specific gravity of this material? 2. Relevant equations specific gravity = (density/density of water) density of water is 1000 kg/m^3 3. The attempt at a solution I don't even know where to start. All my text book says is the specific gravity of a substance is the ratio of its density to the density of the water at 4 degrees C. I don't know how to relate this to an equation or begin to solve it.