A sound source S moves along a straight track with speed v and emits frequency ν₀. A stationary observer O is at a finite distance from the track. Which graph best represents the observed frequency versus time? t₀ is the instant of minimum source-observer distance.
Options

Question

A sound source S moves along a straight track with speed v and emits frequency ν₀. A stationary observer O is at a finite distance from the track. Which graph best represents the observed frequency versus time? t₀ is the instant of minimum source-observer distance.

Options

G1 Physics · Accepted Answer

Step 1: For sound, f' = f(v ± vₒ)/(v ∓ vₛ), with velocities taken relative to the medium. Step 2: Choose signs for approach/recession; for an echo/reflection apply the Doppler shift twice. Step 3: If two frequencies are heard, take their difference for beats. Final: D: Option D.