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**1. Homework Statement**

Two trumpet players tune their instruments to exactly 440 Hz. Find the difference in the apparent frequencies due to the Doppler effect if one plays her instrument while marching away from an observer and the other plays while marching toward the observer. Is this enough to make them sound out of tune? (Assume 1 m/s as a reasonable marching speed).

**2. Homework Equations**

[tex]f=f\frac{V}{V-V_s}[/tex]

and

[tex]f=f\frac{V}{V+V_s}[/tex]

**3. The Attempt at a Solution**

[tex]f=440\frac{343}{343-1}=441 Hz[/tex]

and

[tex]f=440\frac{343}{343+1}=439 Hz[/tex]

However, how should I know whether this is enough to make them sound out of tune? And am I correct with the difference in the apparent frequencies due to the Doppler effect?