Chapter 2: Q10E (page 539)
Question: Energy Delivered to the Ear. Sound is detected when a sound wave causes the tympanic membrane (the eardrum) to vibrate. Typically, the diameter of this membrane is about 8.4 mm in humans. (a) How much energy is delivered to the eardrum each second when someone whispers (20 dB) a secret in your ear? (b) To comprehend how sensitive the ear is to very small amounts of energy, calculate how fast a typical 2.0-mg mosquito would have to fly (in mm/s) to have this amount of kinetic energy.
Short Answer
(a) Energy is delivered to the eardrum each second when someone whispers (20 dB) a secret in your ear is \(5.538 \times {10^{ - 15}}\;{\rm{J}}\) .