Question

Your boss asks you to design a room that can be as soundproof as possible and provides you with three samples of material. The only information on each sample's label is the material's coefficient of absorption. The coefficient of absorption listed on Sample A is 30%, on Sample B is 47%, and on Sample C is 62%. When your boss asks for your choice and the reasoning behind it, what would you tell him? A. Sample A would be best, because the percentage of the energy in an incident wave that remains in a reflected wave from this material is the smallest. B. Sample A would be best, because the percentage of the energy in an incident wave that remains in a reflected wave from this material is the largest. C. Sample C would be best, because the percentage of the energy in an incident wave that remains in a reflected wave from this material is the largest. D. Sample C would be best, because the percentage of the energy in an incident wave that remains in a reflected wave from this material is the smallest.

Answer 1

The correct option is D.
The absorption coefficient of a material refers to the quantity of light of a given colour that is absorbed by a material, which have a particular thickness. When a wave or light is incident on a material, three different things can happen to the light, it can be reflected, transmitted or absorbed. The light that is absorbed is the one that enter into the material and never come out again.The higher the percentage of coefficient of absorption of a material, the more efficient it will be in absorbing light or sound waves. Thus, for the question given above, material C will absorb 62% of the sound leaving only 38% as reflected sound. This means that the material has absorbed most of the sound. Since, this is the material with the highest coefficient absorption, it will be the best material to be used.