Sound waves travel in water about four times their speed in air. When sound waves leave the air and enter the water, does their velocity change? Does their frequency change? Does their wavelength change? Please explain.
2007-02-20 14:27:25 · 2 answers · asked by anime_girl90 2 in Science & Mathematics ➔ Physics
The frequency can't change. Think about the waves as they cross the surface. If there's 100 pulses per second hitting the surface, there has to be 100 per second leaving the surface in the other medium. If there weren't, the waves would be piling up somewhere. Since the velocity changes and the frequency remains constant, the wavelength must change. Wavelength is velocity divided by frequency, so it's four times longer in water.
2007-02-20 15:26:08 · answer #1 · answered by injanier 7 · 0⤊ 0⤋
First sentence answers first question. Yes, velocity changes
Frequency doesn't change. Shake hands with someone under water. Their hand goes up and down at same frequency as yours out of water.
wavelength changes because v changes and f doesn't.
If v goes up, so does wavelength
If v goes down, so does wavelength
v = frequency x wavelength
2007-02-20 14:33:50 · answer #2 · answered by hello 6 · 0⤊ 0⤋