Here are some examples:

* A light flickering: If a light is flickering 5 times per second, it has a frequency of 5Hz.

* A vibrating object: A tuning fork or a speaker emitting a low-frequency sound might vibrate at 5Hz.

* A wave: A wave in water or a radio wave could have a frequency of 5Hz.

* A computer processor: A computer processor might have a clock speed of 5Hz, meaning it performs 5 operations per second.

The specific activity depends on the context. 5Hz is a relatively low frequency, and it's often associated with things that are slow or rhythmic.