Pretest: Waves
18
Select the correct answer.
Which type of wall would make the best soundproofing for room?
OA.
1.0 centimeter thick glass
OB.
two layers of 0.5 centimeter thick glass with 0.5 centimeters of air between them
OC.
two layers of 0.5 centimeter thick glass with 0.3 centimeters of vacuum between them
OD.
1.0 centimeter thick steel