Finding the First Quiet Spot

How Can You Find the First Quiet Spot?

Based on the data, how far from the wall must you move to find the first quiet spot?

Finding the First Quiet Spot

To find the first quiet spot, the distance from the wall needs to be calculated, assuming a sound speed of 340 m/s. The first quiet spot is where destructive interference occurs, and it is also where the sound waves reflected from the wall are out of phase with the sound waves that are directly from the source.

The distance to the first quiet spot from the wall is equal to one-half the wavelength of the sound. The formula for calculating the distance is Distance = (n + 0.5) λn, where n = 1, 2, 3,… and λn = the wavelength of the sound.

The speed of sound in air is about 340 meters per second at standard temperature and pressure. The formula for the wavelength of the sound is λn = v/f, where v = speed of sound and f = frequency of the sound. By calculating the wavelength of the sound and dividing it by 2, you can find the distance to the first quiet spot.

For example, if the frequency of the sound is 1 kHz, the wavelength is calculated as follows: λ = v/f = 340 m/s / 1 kHz = 0.34 m. Therefore, one-half the wavelength is (1/2)λ = 0.17 m. Thus, the first quiet spot is 0.17 meters away from the wall.