What will displace more water- an object with greater mass, or greater volume? For instance, if you have a glass of water and you drop an object in that is heavy (mass), but relatively small in size versus dropping an item that is much larger in size (volume), but not nearly as heavy, which item would displace more? The second part of the question. Assume you had two items of the same size (volume), but two different weights or mass. Would the displacement be the same based on volume, or greater based on mass?