A nebula is a giant cloud of gas and dust in space. Under certain conditions, a nebula can collapse to produce a star over a long period of time.
State the force that causes the initial collapse of the nebula.
Nebula Z-74\text{Z-74}Z-74 is modelled as a sphere of gas and dust particles of diameter 6.8 pc6.8\text{ pc}6.8 pc.
The nebula has 2.4×10112.4 \times 10^{11}2.4×1011 gas and dust particles per m3\text{m}^3m3 and a temperature of 120 K120\text{ K}120 K. The nebula behaves like an ideal gas.
Show that the volume of the nebula is approximately 4.9×1051 m34.9 \times 10^{51}\text{ m}^34.9×1051 m3.
(1 pc=3.1×1016 m1\text{ pc} = 3.1 \times 10^{16}\text{ m}1 pc=3.1×1016 m)
Calculate the total kinetic energy EkE_{\text{k}}Ek of the gas and dust particles in nebula Z-74\text{Z-74}Z-74.
Another nebula, which eventually formed a different planetary system, is estimated to have a diameter of 3.1 pc3.1\text{ pc}3.1 pc and had a similar composition and density to nebula Z-74\text{Z-74}Z-74.
Calculate the ratio
mass of nebula Z-74mass of this second nebula \frac{\text{mass of nebula Z-74}}{\text{mass of this second nebula}} mass of this second nebulamass of nebula Z-74After a long period of stellar evolution, nebula Z-74\text{Z-74}Z-74 will form a star with a mass similar to that of the Sun. Describe the eventual evolution of this solar-mass star after it leaves the main sequence.
