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?

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)