Answer: Hertz.
- A Metre
- B Newton
- C Hertz
- D Pascal
Correct answer: C. Hertz
Explanation: Frequency is measured in Hertz (Hz) = cycles per second.
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.