Prior to discussing how to calculate frequency, let us define it. Frequency is a property of a wave that tells us the number of waves that pass at a fixed point in unit time and the number of cycles completed per unit time.

Frequency is expressed in units of hertz (Hz). The related units include millihertz, kilohertz, megahertz, and gigahertz. The unit is named after Heinrich Rudolf Hertz, the physicist who proved the existence of electromagnetic waves.

### Formula 1 to Calculate Frequency.

To calculate frequency(f) we find the reciprocal of period. Period is the amount of time it takes for one cycle of a repeating event to occur.

**Example 1:**

What is the frequency of a sound wave with a period of 0.04s .

The frequency of the wave is 25 Hz.

### Formula 2 to Determine Frequency.

Wave speed is the velocity of the wave in meters per second.

Wavelength of a wave is the distance between any two corresponding points on adjacent waves

**Example:**

What is the frequency of a sound wavelength that travels with a speed of 340 m/s and its length is 0.15 m.

The frequency of the wave is 2,266.67 Hz.

### Application of Frequency Formula.

- We consider frequency as an important parameter in the fields of science and engineering and so does the frequency formula.
- We use the formula for frequency to specify the rate of oscillatory and vibratory phenomena, mainly the mechanical vibrations, sound, the radio waves, and the light waves.
- Also we use this concept to determine the frequency, time period, wave speed, and wavelength and to derive the other related formulas.