When a 36.7g sample of iron is placed in a graduated cylinder containing 20.0mL, the water level rises to 24.7mL. What is the density of iron?

From Archimedes' principle, when an object with known mass and volume is placed on a container also containing liquid mass and volume, there will be volume displacement. The amount of volume displaced is equal to the volume of the object. The solution is as follows:

Volume displaced = 24.7 mL - 20 mL = 4.7 mL

Density = Mass/Volume = 36.7 g/4.7 mL = 7.81 g/mL