Let's imagine you have a swinging pendulum. It takes exactly 1 second for the pendulum to complete one full swing back and forth.

Here's how to calculate the frequency in Hertz:

* Frequency (Hz) = 1 / Time (seconds)

* Frequency (Hz) = 1 / 1 second

* Frequency (Hz) = 1 Hz

Therefore, the frequency of the pendulum is 1 Hertz. This means it completes one cycle (one full swing) per second.

Another example:

If a sound wave vibrates 440 times per second, its frequency is 440 Hz. This is the frequency of the musical note 'A' above middle C.