(Sound Intensity) A fan at a Metallica concert is a distance away from the stage, and at x that point, the sound intensity level is Assume that the sound being generated β. propagates in the shape of a hemisphere because the point of generation is so close to the ground. How much energy is transferred to the fan’s eardrums each second? What speed would a mosquito of mass have to fly to have this much kinetic m energy? = 30 m x 110 dB = β = 2.0 mg m (Bringing It Together) A sound wave in air at temperature has a frequency of and a T f displacement amplitude of A. What is the pressure amplitude of this wave? What is the intensity of this wave (in W/m2)? What is the sound intensity level (in dB)? = 20 ºC T = 150 Hz f = 5.00*10-3 mm A = 28.97 g/mol Mair = 1.40 γair 8.314 J/mol-K R = = 1.614 kg/m3 ρ
(Sound Intensity) A fan at a Metallica concert is a distance x away from the stage, and at that point, the sound intensity level is β. Assume that the sound being generated propagates in the shape of a hemisphere because the point of generation is so close to the ground. How much energy is transferred to the fan’s eardrums each second? What speed would a mosquito of mass m have to fly to have this much kinetic energy? x = 30 m β = 110 dB m = 2.0 mg (Bringing It Together) A sound wave in air at temperature T has a frequency of f and a displacement amplitude of A. What is the pressure amplitude of this wave? What is the intensity of this wave (in W/m2)? What is the sound intensity level (in dB)? T = 20 ºC f = 150 Hz A = 5.00*10-3 mm Mair = 28.97 g/mol γair = 1.40 R = 8.314 J/mol-K ρ = 1.614 kg/m3
PHYS_221__20-29__Whisnant_wmhutter_Worksheet_28_-_Sound_Waves.docx