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.
A nebula Y\text{Y}Y is modelled as a sphere of gas and dust particles of diameter 8.2 pc8.2\text{ pc}8.2 pc.
The nebula has 1.5 × 1012 gas and dust particles per m3\text{m}^3m3 and a temperature of 180 K. The nebula behaves like an ideal gas.
Show that the volume of the nebula is approximately 8.6 × 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 Y\text{Y}Y.
Another nebula, which eventually formed a different planetary system, is estimated to have a diameter of 4.5 pc4.5\text{ pc}4.5 pc and had a similar composition and density to nebula Y\text{Y}Y.
Calculate the ratio
mass of nebula Ymass of this second nebula \frac{\text{mass of nebula Y}}{\text{mass of this second nebula}} mass of this second nebulamass of nebula YAfter a long period of stellar evolution, nebula Y\text{Y}Y will form a very massive star. Describe the eventual evolution of this massive star after it leaves the main sequence.
66 exam-style questions on OCR A A Level Physics Astrophysics and cosmology, covering Stars, Electromagnetic radiation from stars, and Cosmology. Each one has a worked solution and a mark scheme showing where the marks go.