GCSE physics

• Define the universe


  The universe is made of billions of different galaxies
• What galaxy do we and our sun belong to?

  The Milky Way
• Define a galaxy


  A galaxy is made of billion of stars
• How does a star with a similar mass to our sun evolve?

  Nebula

  Protostar

  Main sequence star

  Red giant

  Planetary nebula

  White dwarf
• How does a star with a bigger mass than our sun evolve?

  Nebula

  Protostar

  Main sequence star

  Red supergiant

  Supernova

  Neutron star OR black hole
• Describe the colour of stars from coldest to hottest

  The coldest stars are red stars ( some main sequence, red giants, red supergiants), and the hottest stars are blue stars (blue giants, white dwarfs, some main sequence)
• What is the calculation for orbital speed?

  Orbital speed= 2 x pi x orbital radius / time period