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hadroneater
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Easy/fustrating doppler question - rather urgent
A swimming duck paddles the water with its feet once per time interval of 1.4 , producing surface waves with this period. The duck is moving at constant speed in a pond where the speed of surface waves is 0.31 , and the crests of the waves ahead of the duck have a spacing of 0.20 .
a)What is the duck's speed?
b)How far apart are the crests behind the duck?
f_d = f_s (v + v_d)/(v + v_s)
There are two things that I don't get. Is the duck the source or the detector of the waves? I think the duck is the source. Then f_s = 1/1.4 = 0.7142Hz
The waves in the front will have f_d = 0.31/0.2 = 1.55Hz and v_d = 0.31m/s
But what is the regular speed of the wave, v? Don't I ned that to solve for v_s?
Homework Statement
A swimming duck paddles the water with its feet once per time interval of 1.4 , producing surface waves with this period. The duck is moving at constant speed in a pond where the speed of surface waves is 0.31 , and the crests of the waves ahead of the duck have a spacing of 0.20 .
a)What is the duck's speed?
b)How far apart are the crests behind the duck?
Homework Equations
f_d = f_s (v + v_d)/(v + v_s)
The Attempt at a Solution
There are two things that I don't get. Is the duck the source or the detector of the waves? I think the duck is the source. Then f_s = 1/1.4 = 0.7142Hz
The waves in the front will have f_d = 0.31/0.2 = 1.55Hz and v_d = 0.31m/s
But what is the regular speed of the wave, v? Don't I ned that to solve for v_s?