What event marked the end of the cretaceous period?

Cretaceous–Paleogene extinction event

Explanation:

The Cretaceous–Paleogene extinction event, also known as the Cretaceous–Tertiary extinction, was a sudden mass extinction

the great extinction

Explanation:  which the dinosaurs died out, except for the birds, of course.

there is no

explanation:

the most common energy conversion is from kinetic energy to potential energy, and then from potential energy to kinetic energy.

later on comes the heat energy, mechanical energy, and other energy conversions.

this energy conversion is so common that we can find it in our day to day lives as well.

- one of the most common energy conversions involves the changing of potential energy to kinetic energy or kinetic energy to potential energy