Two train whistles, A and $B,$ each have a frequency of $392Hz.A$ is stationary and $B$ is moving toward the right $($away from $A)$ at a speed of $35\mathrm{.}0\frac{m}{s}.$ A listener is between the two whistles and is moving toward the right with a speed of $15\mathrm{.}0\frac{m}{s}($Figure $1).$ No wind is blowing. Take the speed of sound to be $344\frac{m}{s}.$

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Part A

What is the frequency from $A$ as heard by the listener?

Express your answer in hertz.

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Part B

What is the frequency from $B$ as heard by the listener?

Express your answer in hertz.

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Part C

What is the beat frequency detected by the listener?

Express your answer in hertz.

$v_A=0$

$v_B=35\mathrm{.}0\frac{m}{s}$

Figure

$1$ of $1$

$(((c(c(i,0)))))$

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$f=$

Hz