**Stationary Wave:** A wave created by the superposition of two progressive waves with the same frequency and amplitude, moving in opposite directions. No energy is transmitted by a stationary wave.

**Resonant frequency:** A frequency at which a stationary wave is formed because an exact number of waves are produced in the time it takes for a wave to get to the end of the vibrating medium and back again. At resonant frequencies, an exact number of half wavelengths fit onto the string.

- You can demonstrate stationary waves by setting up a driving oscillator at one end of a stretched string with the other end fixed. The wave generated is reflected back and forth.
- If at the right frequency, the oscillator will produce the exact number of waves in the time it takes for a wave to get to the end and back again.
- The original and reflected waves reinforce each other.
- These stationary waves are transverse, each particle vibrates at right angles to the string.

**A stationary wave is the superposition of two progressive waves, just two waves interfering:**

- At a node, there is total destructive interference - the displacement of the two waves always cancel each other out.
- At an antinode, there is constructive interference - the displacement of the two waves combine to make a bigger displacement.

## Comments

No comments have yet been made