Rotational kinetic energy

Rotational kinetic energy is the energy associated with spinning around on an axis. It's an energy of motion, just like linear kinetic energy. Molecules get rotational kinetic energy as well, which becomes part of their thermal energy; this can be seen in the molecule's heat capacity.

Rotational kinetic energy depends on the moment of inertia, , which depends both on mass and shape. The equation for rotational kinetic energy is quite similar to that for kinetic energy:

is how much the object resists speeding up or slowing down. is how fast the object spins around.

Flywheels and dynamos spin very fast and have a high moment of inertia in order to store energy. These have been proposed as possible energy storage devices.

To learn more about rotational kinetic energy, please see hyperphysics.