- #1
physics_06er
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Hi could someone please tell me if I have answered these correctly?
1)-Explain how traveling waves can be formed by traveling waves, and hence how the freq's. of a standing waves in an open tube are related to the speed at which sound travels along the tube?
travelling waves formed when to waves traveling in opposite directions with same freq. and amplitude cancel each other out. frequencies of standing waves in open tubes are related to speed by their wavelength. As one whole wavelength is 4 times the length of the tube-we must change the length of tube for different speeds to occur...is something like ok?
2)-in string instruments, unlike most wind instruments, resonances of the body of the instrument play no part in determining pitch. what role do these resonances play in a string instrument, and how is it desirable for them in be distrubuted in freq.?
they amplify sound right?...hmm what else
3)sound level produced by flut is 53dB
a)what pressure amp. is this...can i justuse formula Lp=20log(P/Po) where Lp=53 and Po=2x10^-5
Last one-this is from textbook solution but am unsure why thye do a certain step..
3)Calculate reverberation time for a room 20m x 15m and 8m high..I get all the steps except they when they calculate the area of wall they go..
A=(2x15x8+2x20x8)...why?
Thanks very much
physics_06er
1)-Explain how traveling waves can be formed by traveling waves, and hence how the freq's. of a standing waves in an open tube are related to the speed at which sound travels along the tube?
travelling waves formed when to waves traveling in opposite directions with same freq. and amplitude cancel each other out. frequencies of standing waves in open tubes are related to speed by their wavelength. As one whole wavelength is 4 times the length of the tube-we must change the length of tube for different speeds to occur...is something like ok?
2)-in string instruments, unlike most wind instruments, resonances of the body of the instrument play no part in determining pitch. what role do these resonances play in a string instrument, and how is it desirable for them in be distrubuted in freq.?
they amplify sound right?...hmm what else
3)sound level produced by flut is 53dB
a)what pressure amp. is this...can i justuse formula Lp=20log(P/Po) where Lp=53 and Po=2x10^-5
Last one-this is from textbook solution but am unsure why thye do a certain step..
3)Calculate reverberation time for a room 20m x 15m and 8m high..I get all the steps except they when they calculate the area of wall they go..
A=(2x15x8+2x20x8)...why?
Thanks very much
physics_06er