Year 10 term 3 Flashcards
(23 cards)
WHat is the univers
a collection of galaxies
what is a galaxy
a collection of stars
what galaxy are we in
the milky way
why may gravitational field strength differ?
the mass of the planet
sun has 99% of the galaxy mass
gravitational field is always —– to the velocity
perpendicular
v=2(pi)r/t
what happens when r decreases
v increases
things the g can effect
- orbit of sattelites
- comet and planets orbit sun
- weight
how do you classify a star
= hottestby colour; blue-
stage one of star
nebula: dust with hydroge and hellium
stage 2 of star
protostar-hot ball of gases from g firce. More density and temperature as closer particle collisions
stage 3 of star
main star sequence- nuclear fusion of H to He, pressure and star is formed. Now inside pressure is same as outside expanding gases
What is neuclar fusion
2 light nuclei make a strogner nuclei
stage4 of solar mass star
red giant- All H is He so no more fusion, pressure inside dec, smallr SA. But the pressure inc so becomes red star
so as core shrinks outer expands
stage 5 of star
planteary nebule- starts to eject the outer expanded layer into dust
stage 6 of star
white dwarf- the planteary nebula gases of outer are gone
stage 7 of star
black dwarf
hwo to determine brightness fo star
magnitude- brighter the star the smaller the magnitude
stage 4 of high mass star
red supergiant; outer expand and contract until iron(as after iron need input for core
stage 5 of high mass star
supernova; collapsed explosion. ejected can become star and planets
stage 6 of high mass star
neutron star or black hole
neutron star
as gravity crushes anymatter into neutrons, are dense but smal
black hole
densest ever, even light cannot escape
