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mukimuki2
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problem How and which equation?? Please help me!
At a height of 10 meters above the surface of a lake, a sound pulse is generated. The echo from the bottom of the lake returns to the point of origin 0.140 s later. The air and water temperatures are 20°C. How deep is the lake?
equations
d=vt
v=wavelength*frequency
wavelength = 4(L + 0.4d)
Vsound = 331.5m/s + .6T
ok here's what I got from a friend and I know its right but...
Speed in air: 343 m/s Speed in water: 1482 m/s
Time in air = 20/343 = 0.058 s
Time in water = 0.140 - 0.058 = 0.082 s
Time to hit bottom: 0.082 / 2 = 0.041 s
d = 1482 (0.041) = 60.8 m
...where did the 20 come from on "Time in Air"? is it 10 x 2?
At a height of 10 meters above the surface of a lake, a sound pulse is generated. The echo from the bottom of the lake returns to the point of origin 0.140 s later. The air and water temperatures are 20°C. How deep is the lake?
equations
d=vt
v=wavelength*frequency
wavelength = 4(L + 0.4d)
Vsound = 331.5m/s + .6T
ok here's what I got from a friend and I know its right but...
Speed in air: 343 m/s Speed in water: 1482 m/s
Time in air = 20/343 = 0.058 s
Time in water = 0.140 - 0.058 = 0.082 s
Time to hit bottom: 0.082 / 2 = 0.041 s
d = 1482 (0.041) = 60.8 m
...where did the 20 come from on "Time in Air"? is it 10 x 2?
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