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 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.
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 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.
 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.
Sound proofing is usually achieved by using materials that absorbed or reduce sounds. Different materials are used in sounding proofing and these differ in their abilities to absorb or reduce sounds. The coefficient of absorption of a material refers to that material ability to absorb sound. The higher the percentage of a material absorption coefficient, the better the material's ability to absorb sound. Thus, in the question given above, the material with 62% absorption coefficient have the greatest ability of the three materials to absorb sound effectively.