To verify her suspicion that a rock specimen is hollow, a geologist weighs the specimen in air and in water. She finds that the specimen weighs twice as much in air as it does in water. The solid part of the specimen has a density of 5.13×103kg/m3. What fraction of the specimen's apparent volume is solid? I tried setting up a ratio of densities but it didn't work at all... please help! I also need help with this one: A geologist finds that a moon rock whose mass is 9.22kg has an apparent mass of 5.58kg when submerged in water. What is the density of the rock? I tried using the equation W=pvg and it didn't get me the right answer.