Energy
The specific orbital energy is negative, and
Thus the virial theorem applies even without taking a time-average:
- the kinetic energy of the system is equal to the absolute value of the total energy
- the potential energy of the system is equal to twice the total energy
The escape velocity from any distance is √2 times the speed in a circular orbit at that distance: the kinetic energy is twice as much, hence the total energy is zero.
Read more about this topic: Circular Orbit
Famous quotes containing the word energy:
“Long before Einstein told us that matter is energy, Machiavelli and Hobbes and other modern political philosophers defined man as a lump of matter whose most politically relevant attribute is a form of energy called “self-interestedness.” This was not a portrait of man “warts and all.” It was all wart.”
—George F. Will (b. 1941)
“There are no accidents, only nature throwing her weight around. Even the bomb merely releases energy that nature has put there. Nuclear war would be just a spark in the grandeur of space. Nor can radiation “alter” nature: she will absorb it all. After the bomb, nature will pick up the cards we have spilled, shuffle them, and begin her game again.”
—Camille Paglia (b. 1947)
“Just as we need to encourage women to test life’s many options, we need to acknowledge real limits of energy and resources. It would be pointless and cruel to prescribe role combination for every woman at each moment of her life. Life has its seasons. There are moments when a woman ought to invest emotionally in many different roles, and other moments when she may need to conserve her psychological energies.”
—Faye J. Crosby (20th century)