Question

Four cubes of the same volume are made of different materials: lead (density 11,300 kg/m3), aluminum (density 2700 kg/m3), wood (density 800 kg/m3), and Styrofoam (density 50 kg/m3). You place the cubes in a large container filled with water.

Answer 1

Answer:

1. Lead

2. Aluminum

3. Wood

4. Styrofoam

Explanation:

Specific gravity is a quantity that tells me how much an object is submerged on a fluid relating the densities:

$S.G=\frac{\rho_{object}}{\rho_{fluid}}$

Because all the cubes are placed on water, the density of the fluid is the same for all the cubes and S.G. is directly proportional to the density of the cube material. So, for greater density greater S.G.

The Archimedes principle states that the buoyant force is equal to the weight of water displaced, that is:

$\overrightarrow{B}=-\overrightarrow{W_{displaced}}$

So, the cube that submerges more is the cube that mor displace water and is the cube that has more buoyant force on it. In other words, the cubes with higher S.G. have more buoyant force, and because S.G is proportional to cube density, the cubes with more buoyant force have more density.