The type of transfer where fast particles collide with slower particles is called heat transfer by conduction.

Here's why:

* Conduction is the transfer of heat energy through direct contact between molecules.

* When a fast-moving particle collides with a slower-moving particle, it transfers some of its kinetic energy to the slower particle. This makes the slower particle move faster, increasing its temperature.

Let me know if you'd like to learn more about different types of heat transfer!