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 tendencies of the times favor the idea of self-government, and leave the individual, for all code, to the rewards and penalties of his own constitution, which work with more energy than we believe, whilst we depend on artificial restraints.”
—Ralph Waldo Emerson (1803–1882)
“All my energy and attention were devoted to trying to help her solve her problems. Unfortunately I didn’t have much success.”
—Arthur Miller (b. 1915)
“Just as we are learning to value and conserve the air we breathe, the water we drink, the energy we use, we must learn to value and conserve our capacity for nurture. Otherwise, in the name of human potential we will slowly but surely erode the source of our humanity.”
—Elaine Heffner (20th century)