Question: A sound wave with a frequency of 400 Hz travels through air with a speed of 343 m/s. If the amplitude of the wave is 0.02 m, calculate the maximum and minimum pressure exerted by the sound wave on the air.
Answer: To calculate the maximum and minimum pressure exerted by the sound wave, we can use the equation for the pressure amplitude of a sound wave:
where
We can use the given frequency to calculate the angular frequency: [ \omega = 2\cdot\pi\cdot400, \text{Hz} = 800\cdot\pi, \text{rad/s} ]
Now, we can calculate the maximum and minimum pressures: [ P_{\text{max}} = 101325 + 1.2 \cdot 343 \cdot 800\pi \cdot 0.02 ] [ P_{\text{min}} = 101325 - 1.2 \cdot 343 \cdot 800\pi \cdot 0.02 ]
Using a calculator to evaluate these expressions: [ P_{\text{max}} \approx 110594 , \text{Pa} ] [ P_{\text{min}} \approx 92056 , \text{Pa} ]
So, the maximum pressure exerted by the sound wave on the air is 110594 Pa, and the minimum pressure is 92056 Pa.