Author Question: What are the three types of pressure that can push against the inward force of gravity? Explain what ... (Read 64 times)

sdfghj · **on:** Jul 27, 2018

What are the three types of pressure that can push against the inward force of gravity? Explain what causes each pressure and where it would be likely to occur.

What will be an ideal response?

Question 2

Planetary orbits that are face-on to our line of sight produce no Doppler shift in the stellar spectrum.

Indicate whether the statement is true or false

billybob123 · **Reply #1 on:** Jul 27, 2018

Answer to Question 1

(1 ) Thermal pressure occurs when the particles inside a star are heated enough so that their random motions cause an outward pressure. The two energy sources of internal thermal pressure are gravitational contraction, found in protostars and when a star has used up a fusionable material in its core, and nuclear fusion, which can occur in the core or in a shell of a star.
(2 ) Degeneracy pressure arises from the idea of quantum mechanics that two electrons (or neutrons) cannot occupy the same state. Degeneracy pressure occurs in the cores of low-mass stars before a helium flash, maintains equilibrium in white dwarfs and neutron stars, and may be present immediately before a supernova event.
(3 ) Radiation pressure exists only in massive stars where fusion rates are so high that photons transfer momentum to the surrounding gas and apply a third kind of pressure.

Answer to Question 2

TRUE