A stationary sound source emitting a frequency of 660 Hz and a large stationary wall are separated by a certain distance. An observer is moving along the straight line joining the source and the wall, travelling directly towards the source at a constant speed u m s ⁻¹ . The observer hears a beat frequency of 16 Hz due to the superposition of the sound received directly from the source and the sound reflected from the

Step-by-step solution

The observer is moving towards the stationary source with speed u . The frequency of the direct sound heard by the observer is: f_ dir = f₀ ( v + u v ) The sound from the source travels to the stationary wall and is reflected. The wall acts as a stationary source emitting the original frequency f₀ . Since the observer is moving away from the wall (towards the source), the frequency of the reflected sound heard by the observer is: f_ ref = f₀ ( v - u v ) The beat frequency is the difference between these two frequen