On a hot afternoon, you\'re watching the rehearsal of a marching band on a level

Question

On a hot afternoon, you're watching the rehearsal of a marching band on a level field. You are standing 9.48 m from a flute player, who is also standing still, playing a single steady note, which happens to be the 2nd harmonic frequency of the flute (which is basically a tube that is open at both ends). A trumpet player, standing the same distance away, is trying to play the same note, but his instrument is out of tune, and you hear a beat frequency of 3.00 Hz. But when the trumpeter marches toward you at a speed of 1.4 m/s, the beats disappear. The speed of sound this day is 350 m/s. How long is the flute? As the trumpeter walks toward you, he passes certain points where you can't hear much from either the flute or the trumpet. One such distance is 7.38 m from you. What is the next distance closer to you?

Explanation / Answer

Wavelength=L

Frequency=350/L

Frequency of player=f=(350/L) -3

If marching toward me

Frequency=f(350+1.4)/350=350/L

Solving for L

We got L=0.46 m

(b)second distance will be

=9.48-(7.38-(L/4))=7.26 m

Related Questions

Navigate

• Browse (All)
• Browse O
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.