Answer: 340 m/s.
- A 170 m/s
- B 340 m/s
- C 510 m/s
- D 680 m/s
Correct answer: B. 340 m/s
Explanation: Consecutive resonance lengths differ by lambda/2. Lambda/2 = 51-17 = 34 cm. Lambda = 68 cm = 0.68 m. v = f x lambda = 500 x 0.68 = 340 m/s.
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.