Energy
Under standard assumptions, specific orbital energy of elliptic orbit is negative and the orbital energy conservation equation (the Vis-viva equation) for this orbit can take the form:
where:
- is orbital speed of orbiting body,
- is distance of orbiting body from central body,
- is length of semi-major axis,
- is standard gravitational parameter.
Conclusions:
- For a given semi-major axis the specific orbital energy is independent of the eccentricity.
Using the virial theorem we find:
- the time-average of the specific potential energy is equal to 2ε
- the time-average of r−1 is a−1
- the time-average of the specific kinetic energy is equal to –ε
Read more about this topic: Elliptic Orbit
Famous quotes containing the word energy:
“The principle of avoiding the unnecessary expenditure of energy has enabled the species to survive in a world full of stimuli; but it prevents the survival of the aristocracy.”
—Rebecca West (1892–1983)
“Children are intensely invested in getting their way. They will devote more emotional and intellectual energy to winning arguments than parents ever will, and are almost always better rested.”
—Jean Callahan (20th century)
“I have witnessed the tremendous energy of the masses. On this foundation it is possible to accomplish any task whatsoever.”
—Mao Zedong (1893–1976)