While it's not technically "speed", kinetic energy is directly related to the speed of the particles. Here's why:
* Kinetic energy is the energy of motion. The faster a particle moves, the more kinetic energy it has.
* Temperature is a measure of the average kinetic energy of particles in a substance.
So, while we don't directly measure the average speed of particles, we can measure the temperature, which tells us about the average kinetic energy and therefore gives us an indication of the average speed of the particles.
