The speed of sound in dry air at 20 °C is 343 m/s and the lowest
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Question

The speed of sound in dry air at 20 °C is 343 m/s and the lowest
frequency sound wave that the human ear can detect is approximately 20 Hz. (b) What would be the frequency of electromagnetic radiation with the same wavelength?

Accepted Answer

Hey everyone, we're told that the speed of sound is faster in water than in air And it has a speed of 1480 m/s. The lowest frequency is 400 MHz. And they want us to calculate the frequency of electromagnetic radiation that would have the same wavelength as a sound wave described First. Let's go ahead and calculate the wavelength with a frequency of 400 MHz. And our formula is going to be wavelength equals our speed divided by our frequency. So plugging in their values, we get m/s. And we're going to divide this by our 400 MHz. And let's go ahead and convert our megahertz into hertz. Now we know that per one megahertz, we have 10 to the six hertz. And when we calculate this out, we end up with a value of 3.7 times 10 to the - m. Now, let's go ahead and calculate the frequency of electromagnetic radiation that has the same wavelength as the sound wave described. So we're going to take our frequency and this is going to be equal to our speed divided by our wavelength. Plugging in our values. We know that our speed is 3.0 times 10 to the 8th m/s. And we're going to divide this by our wavelength, which we just calculated as 3.7 times 10 to the negative six m. And when we calculate this out, we end up with a total of 8.10 times 10 to the 13 hertz, which is going to be our final answer. So I hope that made sense and let us know if you have any questions.

The speed of sound in dry air at 20 °C is 343 m/s and the lowest frequency sound wave that the human ear can detect is approximately 20 Hz. (b) What would be the frequency of electromagnetic radiation with the same wavelength?

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