Answer: 333 Hz.
- A 270 Hz
- B 300 Hz
- C 333 Hz
- D 340 Hz
Correct answer: C. 333 Hz
Explanation: f' = f·v/(v − v<sub>s</sub>) = 300·340/306 ≈ 333 Hz.
A standing wave forms from two identical waves travelling in opposite directions and interfering; nodes (always zero displacement) and antinodes (maximum displacement) stay fixed in place, unlike a travelling wave where the whole pattern moves.
Concept context
Wave types, superposition, standing waves, Doppler effect, and sound intensity.