**Amplitude**

Amplitude is the maximum displacement from the rest or central position, in either directions.

- SI unit is metre
- Scalar quantity

**Frequency**

Frequency (f) is defined as the number of complete waves produced per unit time.

- SI unit is hertz (Hz) – 1 Hz = 1 complete cycle per second
- Scalar quantity
**Determined by the source**(for water waves)

**Wavelength**

Wavelength (λ) is the distance between corresponding points of two consecutive waves.

- SI unit is metre
- Scalar quantity

**Speed**

Speed of the wave propagation is defined as the distance travelled by a wave per unit time.

- SI unit is metre per second (m s
^{-1}) - Scalar quantity

**Period**

Period (T) is defined as the time taken to produce one complete wave.

- SI unit is second (s)
- Scalar quantity
- $T = \frac{1}{f}$

**Velocity**

Velocity is the distance travelled by a wave in one second.

- SI unit is metres per second (m s
^{-1}) - Vector quantity
- $v = f \lambda$ (Important!)