You are standing 2.5 m , directly in front of one of the two loudspeakers shown

Question

You are standing 2.5 m ,directly in front of one of the two loudspeakers shown in the figure. They are 3.0 m apart and both are playing a 686 Hztone in phase.

As you begin to walk directly away from the speaker, at what distances from the speaker do you hear aminimum sound intensity? The room temperature is 20 degree C.

x= ????????

You are standing 2.5 m ,directly in front of one of the two loudspeakers shown in the figure. They are 3.0 m apart and both are playing a 686 Hztone in phase. As you begin to walk directly away from the speaker, at what distances from the speaker do you hear aminimum sound intensity? The room temperature is 20 degree C.

Explanation / Answer

f = 686 Hz


at t = 20 degrees celsius

v = 331 + 0.6*20 = 343 m/s


v = laamda*f

lamda = v/f = 343/686 = 0.5m (wavelength)


r1 = 2.5 m

r2 = sqrt(2.5^2 + 3^2) = 3.905 m

initial path difference, (r2-r1 = 3.905 - 2.5 = 1.405

condition for minimum sound

r2-r1 = lamda/2 or 3*lamda/2 or 5*lamda/2 or 7*lamda/2.......


here initially, r2-r1 > 5*lamda/2

so, next posibility

(r2-r1)' = 7*lamda/2

(r2-r1) = 7*0.5/2

(r2-r1)' = 1.75 m


so the person has to move 1.75 - 1.405 = 0.345 m

Related Questions

Navigate

• Browse (All)
• Browse Y
• Subjects

---

---

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