P1 astrophysics

• What is the formula for weight?

  Weight = mass x g
• Why does weight vary across planets?

  Weight varies due to different gravitational strengths
• What does our solar system consist of?

  Sun, planets, moons, dwarf planets, comets, asteroids
• Describe the orbits of moons, planets, comets, and artificial satellites.

  • Planets: approximately circular orbits around the Sun
  • Moons: approximately circular orbits around planets
  • Comets: elliptical orbits around the Sun
• What force causes astronomical objects to follow orbits?

  Gravitational force
• What astronomical object forms from billions of stars?

  A galaxy
• What is the name of the galaxy that contains our solar system?

  Milky Way galaxy
• What is the large collection of billions of galaxies called?

  The Universe
• What is the equation linking orbital speed, orbital radius, and time period?


  Not provided in the material

  
• Order the colours of stars from coldest to hottest.

  • Red
  • Orange
  • Yellow
  • White
  • Blue
• What is a nebula?

  A cloud of gas and dust
• Describe the transition of a star from the nebula stage to the main sequence.

  • Nebula increases in size due to gravity
  • GPE converts to KE of molecules
  • Temperature increases as particles collide
  • Nebula becomes dense and hot enough for fusion
• What occurs when a star is in the main sequence stage?

  Fusion releases energy, mainly turning hydrogen into helium
• What happens when a star transitions to the red giant stage?

  Star fuses helium and expands into a red giant
• How does a star become a white dwarf from a red giant?

  Gravity pulls in mass, forming a small, dense white dwarf
• What stages occur for the evolution of stars larger than the sun?

  • Nebula
  • Main sequence star
  • Red supergiant star
  • Supernova
  • Black hole/neutron star
• What is a supernova?

  Explosion of a star after the red supergiant stage