Hearing the siren of an approaching fire truck, you pull over to the side of the

Question

Hearing the siren of an approaching fire truck, you pull over to the side of the road and stop. As the truck approaches, you hear a tone of 467 Hz; as the truck receded, you hear a tone of 410 Hz. How much time will it take for the truck to get from your position to the fire 6.2km away, assuming it maintains a constant speed?
Min?? Hearing the siren of an approaching fire truck, you pull over to the side of the road and stop. As the truck approaches, you hear a tone of 467 Hz; as the truck receded, you hear a tone of 410 Hz. How much time will it take for the truck to get from your position to the fire 6.2km away, assuming it maintains a constant speed?
Min??
Min??

Explanation / Answer

Equation for Doppler shift is given by,
f/= f (v +/- vO) / (v -/+ vs)
For case 1,
f' = 467 Hz
v = 343 m/s
Vo = 0
Vs = Velocity of truck = ?

Substituting Values,
467 = f* (343)/(343 - Vs) -----1

For Case 2,
f' = 467 Hz

410 = f* (343)/(343 + Vs) -------2

Solvinf eq 1 & 2,
Vs = 22.3 m/s

Time = Distance/Speed
t = (6.2 * 10^3)/22.3
t = 278.0 s
t = 4.63 min

Related Questions

Navigate

• Browse (All)
• Browse H
• Subjects

---

---

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