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:
“Perhaps catastrophe is the natural human environment, and even though we spend a good deal of energy trying to get away from it, we are programmed for survival amid catastrophe.”
—Germaine Greer (b. 1939)
“Because humans are not alone in exhibiting such behavior—bees stockpile royal jelly, birds feather their nests, mice shred paper—it’s possible that a pregnant woman who scrubs her house from floor to ceiling [just before her baby is born] is responding to a biological imperative . . . . Of course there are those who believe that . . . the burst of energy that propels a pregnant woman to clean her house is a perfectly natural response to their mother’s impending visit.”
—Mary Arrigo (20th century)
“Since the beginning of time, three-quarters of the mental energy and of the lies inspired by vanity have been expended for their inferiors by people who are only abased by such expenditure. And Swann, who was easygoing and unaffected with a duchess, trembled at the thought of being scorned and put on airs when he was with a housemaid.”
—Marcel Proust (1871–1922)