what is the variation of pressure in the sound wave if the sound intensity is 3.85x10^-8 W/m^2, the speed of sound is 343 m/s and the density of air is 1.2 kg/m3?
To determine the variation of pressure in a sound wave, you can use the formula:
ΔP = √(2 * I * ρ * v)
Where:
ΔP = variation of pressure
I = sound intensity
ρ = density of the medium
v = speed of sound
Given:
I = 3.85x10^-8 W/m^2
ρ = 1.2 kg/m^3
v = 343 m/s
Now, substitute the values into the formula:
ΔP = √(2 * 3.85x10^-8 * 1.2 * 343)
First, multiply the numbers inside the square root:
ΔP = √(2 * 4.62x10^-8 * 343)
Next, calculate the product:
ΔP = √(3.1672x10^-5)
Take the square root:
ΔP ≈ 0.00562657
Rounded to the appropriate number of significant figures, the variation of pressure in the sound wave is approximately 0.0056 Pascal (Pa).