Answer: 50 m/s.
- A 25 m/s
- B 50 m/s
- C 100 m/s
- D 200 m/s
Correct answer: B. 50 m/s
Explanation: Standing wave: y = 2A sin(kx) cos(omega t). k=4, omega=200. v = omega/k = 200/4 = 50 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.