When a sound wave propagates past a point in the air, what are the changes that occur in the pressure of air at this point?
Suppose you wish to produce a sound wave that has a wavelength of 8 m in room-temperature air. What would its frequency be?
A bat flying in a cave emits a sound pulse and receives its echo in 1.4 s. How far away is the cave wall?
2007-03-13 11:59:45 · 2 answers · asked by thatsfunnybunny 2 in Science & Mathematics ➔ Physics
i really dont get these...i need an explanation at least for one of them...please
2007-03-13 12:15:28 · update #1
1. If the sound is a single frequency, the pressure varies sinusoidally about a mean value which is the atmospheric pressure. A more complex sound will register a more complex pressure variation.
2. Assuming a sound velocity of 344 m/sec, the frequency would be 344/8 Hz.
3. Again assuming a sound velocity of 344 m/sec, the wall is 0.5*1.4*344 m away. (You use half the echo time because the sound travels to the wall and back to the bat in that time.)
2007-03-13 13:13:13 · answer #1 · answered by kirchwey 7 · 0⤊ 0⤋
2nd and 3rd, you need the speed of sound
2007-03-16 13:39:25 · answer #2 · answered by arbiter007 6 · 0⤊ 0⤋