space Flashcards
whats a natural satalite?
the moon
whats the star cycle?
cloud of dust and gas(nebula) , protostar, main sequence star
stars bigger than the sun?
red super giant, super nova, black hole or neutron star.
stars same size as sun?
red giant, white dwarf, black dwarf
what happens when hydrogen runs out?
star swells into red giant or red super giant
what does the force of gravity do?
pulls dust and gas together to form protostar.
what happens when temperature is high enough?
hydrogen nuclei undergo nuclear fusion to form helium nuclei.
whats a main sequence star?
long stable period, outwards pressure tries to expand star balances the force of gravity, everything pulled inwards.
whats formed in a supernova?
elements heavier than iron
what do planets do?
orbit the sun
what are moons?
natural satalites
what orbits do planets move round the sun?
circular orbits, constantly changing direction and constantly accelerating.
where is the force direction for acceleration?
the centre
what keeps the object turning in a circle?
instantanious velocity
where is gravitational force greatest?
closer to the star or planet
