How do you find the density of an irregular shaped object that also reacts with water?

Answer 1

We will assume there is no difficulty in weighing the object, so the problem becomes how to measure the volume of the object accurately enough to calculate the density within a reasonable degree of certainty. There are several possible ways.

1. Immerse the object in a non-reactive liquid (oil, perhaps) and measure the amount of liquid displaced.
2. Apply a thin coat of insulating material (paint, or wax) all over the object, and then immerse the coated object in water and measure the amount of water displaced.
3. Cut the object into a group of regular geometric shapes (boxes, spheres, prisms, cones, pyramids, etc.), and measure the dimensions of each geometric shape, and calculate the aggregate volume (destructive, and less accurate)
4. Drill a cylindrical core sample of the object, weigh the sample, and precisely measure the dimensions of the cylindrical sample to calculate volume (destructive, and assumes the density of the object is uniform)
5. Make a clay, wax, or other mold of the object, and measure the volume of the mold.
6. Place the object in an three dimensional laser scanner and compute the volume using the software in the scanner computer.