Rotational kinetic energy
Rotational kinetic energy depends on:
- How fast the object is spinning (faster spinning means more energy).
- How much mass the spinning object has (more massive means more energy).
- Where the mass is located compared to the spin (objects farther from the spinning axis have more rotational kinetic energy).
Some physical systems where rotational kinetic energy is important include:
- Flywheels (Figure 1) and dynamos which spin very fast and have a high moment of inertia in order to store energy. These have been proposed as possible energy storage devices.
- Molecules get rotational kinetic energy, which becomes part of their thermal energy; this can be seen in the molecule's heat capacity.
- Turbines are turning the energy in a fluid into rotational kinetic energy. This energy is then turned into electricity with a generator.
- The Earth has rotational kinetic energy associated with going spinning around its axis once a day (roughly 38 Octillian Joules).)
- The Earth has rotational kinetic energy associated with orbiting the sun once a year (roughly 2,700,000 Octillian Joules).)
To learn more about rotational kinetic energy, please see hyperphysics.
For Further Reading
- flywheel of the Boulton-Watt steam engine", Flickr, 2018. [Online]. Available: https://www.flickr.com/photos/newtown_grafitti/4803665199. [Accessed: 15- Jun- 2018].
- That's joules, or 38 billion billion billion joules.
- That's joules, or 2.7 million billion billion billion joules. Roughly 100,000x the amount of energy of the Earth spinning on its axis.