astrophysics Flashcards
how does your weight vary across planets?
your weight is calculated by mass x weight
the gravitational field strength varies depending on the raidius and mass of that planet
this means your weight will aslo vary
what does the solar system consist of?
the sun
8 planets
the planet’s natural satellite like the moon
dwarf planets
comets and asteroids
describe the orbits of the moons, planets, comets and artificial satellites?
planets - circular orbit around the sun
comets - elliptical orbit around the sun
artificial satellites and the moon - circular orbit around the planets
which force makes astronomical objects follow an orbit?
gravitational force pulls the objects causing them to follow orbits around massive objects
which astronomical object forms from the collection of a billion 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
state the equation linking orbital speed, orbital radius and time period
Orbital speed = 2 x pix orbital radius
time period
starts can be classified according to colour give the order of coldest to hottest colour
red
orange
yellow
white
blue
name each stage the sun will or has gone through in its life
nebula
main sequence star (currently in this stage)
red giant
white dwarf
what is a nebula
a cloud of gas and dust
describe the transition of a star from nebula to a main sequence star
1 nebula increases in size until it is pulled in due to gravity - causing GPE to turn into KE molecules
2 as it gets smaller - particles move faster and collide harder increasing the temperature
3 eventually nebula will become hot and dense enough to being fusion
what occurs in the stage where the star is a main sequence star?
- fusion in the star releases energy
- during fusion the main sequence star minly turns hydrogen into helium
- thermal energy released from fusion causes an outward pressure which balances the inward pressure caused by gravity
what happens when a star transitions to a red giant?
- once all of the hydrogen fuel has been used up, the start begins to fuel helium and other larger nuclei
- this causes the start to expand and become a red giant
how does a star transition from red giant to white dwarf?
- once all of the reactions have taken place the stars gravity pulls in all of its mass, making it a small and dense white dwarf
- this will cool down to form a black dwarf
what is a supernova?
after the red supergiant stage the star will expand and get hotter and eventually explode as a supernova
what is left turns into a neutron star (black hole if it is very large)
difference in the energy release of the core of a star and a power station
Energy release in a star occurs through nuclear fusion, where hydrogen nuclei combine to form helium, resulting in significant energy output. In contrast, energy in a nuclear reactor is produced by nuclear fission, where heavy atomic nuclei split into smaller ones, releasing energy.
