Question

g 3. Doppler Shift (easy). As you sit out on the grass enjoying a sunny day, someone else in the park is flying a very annoying drone that is emitting sound at 600 Hz. The drone flies over head with a velocity of 30 m/s. What frequency do you hear as the drone approaches? What frequency do you hear after it has passed and is moving away from you?

Answer 1

Answer:

Frequency when drone approaches = 657.50 Hz (Approx)

Frequency when drone passed = 551.74 Hz (Approx)

Explanation:

Given:

Frequency = 600 Hz

Velocity before (v₁) = 30 m/s

Velocity after (v₂) = -30 m/s

Find:

Frequency when drone approaches = ?

Frequency when drone passed = ?

Computation:

We, know that speed of sound (V) = 343 m/s

Frequency when drone approaches = [V/(V-v₁)]Frequency

Frequency when drone approaches = [343/(343-30)]600

Frequency when drone approaches = [343/(313)]600

Frequency when drone approaches = 657.50 Hz (Approx)

Frequency when drone passed = [V/(V-v₂)]Frequency

Frequency when drone passed = [343/(343-(-30))]600

Frequency when drone passed = 551.74 Hz (Approx)