5. Given that the speed of sound in air is 343 m/s (density 1.204 kg/m3) and tha

Question

5. Given that the speed of sound in air is 343 m/s (density 1.204 kg/m3) and that the speed of sound in helium gas is 275 m/s (density 1.00 kg/m3).

(A) Calculate the acoustic impedance for both air and helium.

(B) Calculate the proportion of the wave that is reflected and the proportion of the wave that is transmitted when the wave moves from air into helium

6.During an extremely loud sound, the amplitude of the pressure wave in air is 1025 Pa and the acoustic impedance, Zair, is from question 5. Calculate the intensity level and power level of the sound in dB.

Please show me how you got this answer! Thank you so much in advance! :)

Explanation / Answer

The absolute value of this specific acoustic impedance is often called characteristic specific acoustic impedance and denoted z0:[1]

For Air

Z0 = Speed of sound * Density of media

= 343 x 1.204

= 412.972 Pa·s/m

For Helium

Z0 = 275 x 1.00

= 275 Pa·s/m

6. The intesity of the sound level is given by

Intensity = Sound Pressure x Particle Velocity

= 1025 x 343

= 351575 watt per square meter

Sound power is related to sound energy density:

Power = Area x Sound Intensty

if we know the are we can find the Power of sound

Related Questions

Navigate

• Browse (All)
• Browse 5
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.