Thursday
March 30, 2017

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the distance between a loudspeaker and the left ear of a listener is 2.70 m a) calculate the time required for sound to travel this distance if the air temperature is 20oC. b) assuming that the sound frequency is 523 Hz, how many wavelengths of sound are contained in this distance?

• physics - ,

The speed of sound in an ideal gas is given by the relationship

• R = the universal gas constant = 8.314 J/mol K,
• T = the absolute temperature
• M = the molecular weight of the gas in kg/mol
•  = the adiabatic constant, characteristic of the specific gas
For air, the adiabatic constant γ = 1.4 and the average molecular mass for dry air is 28.95 gm/mol. At T = 200C = 293.160C,
vsound = 343.32 m/s
Time = Distance/speed = 2.70/343.32 = 7.86 ms

b) Assuming that the sound frequency is 523 Hz, how many wavelengths of sound are contained in this distance?
v = n
Number of wavelnegths contained in 2.7 m =