READING 2 The eardrum is displaced surprisingly little when asound wave strikes it. Some idea of the displacement of the eardrumby a sound wave can be obtained by using Equation 7.1: Equation forwave energy The displacement amplitude, A, of the air moleculesgives us a lower limit to the displacement of the eardrum.
At the threshold of hearing at 3.4 kHz, the sound intensity isabout 10−12W/m2. The threshold of pain begins at an intensity of1.0W/m2 (19).
What is the amplitude of eardrum vibrations at theseintensities?
The density of air is 1.3kg/m3. The speed of sound is331m/s.
Please write your answers with one decimal places.
(________________10^−3 nm (at threshold of hearing) (This valueis ~ 3/100 the diameter of a hydrogen atom!)
________________10^3 nm (at threshold of pain)
I believe the answer to the first question is 3.19 x to^-3nm
