topic 8 space Flashcards
which galaxy is our solar system part of
the milky way
what type of force pulled together the cold of dust and gas to form the sun
gravitational force of attraction
what word is used to describe a could of dust and gas
a nebula
what type of reaction takes place when dust and gas is drawn together
fusion reactions
what factor determines the type of lifecycle a star undergoes
size of star
which two phases do all stars undergo
protostar phase
main sequence phase
what is the protostar phase
when all cloud and dust are pulled together with the gravitational force of attraction
what is the main sequence star
when the outward pressure caused by the nuclear fusion is the same as the force of gravity pulling everything inwards
what two thing can star much bigger than the sun become at the end of their life cycle
neutron star
black hole
what conditions are required for fusion reactions to occur in a star
very high temperatures
how are elements heavier than iron produced
in a supernova
what fuses together to form heavier elements in a star
hydrogen nuclei fuse to form heavier elements
how are elements distributed throughout the universe
through the explosion of a massive star
what allows planets and satellites to maintain circular orbits
gravity provides the gravitational force that acts as the objects centripetal force
the presence of centripetal force allows for the object to maintain its circular orbit
what type of satellite can a planets moon be described as
a natural satellite
give two examples of artificial satellites
tv satellites
satellites used for satellite imaging
explain why for a stable orbit, the radius of orbit must change if the speed changes
at higher speeds, the object requires a greater centripetal force
for greater centripetal force the gravitational force must increase
this is achieved by the radius of the orbit being reduced
explain how the force of gravity acting on a satellite affects its speed and velocity
the force can altar its velocity since the direction is continually changing
it cant cause a change of speed since there is no force component in the direction of motion
what is red shift
an observed increase in the wavelength of light from distant galaxies
what two things can be said about the motion and wavelength of emitted light from a galaxy, the further away it is?
the further the galaxy the faster its moving
the further away the galaxy is the greater the observed increase in wavelength
what does redshift provide evidence for
provides that the universe is still expanding
supports big bang theory
what does big bang suggest
the entire universe started from a very hot and dense region in space
what can you say about redshift and movement when a galaxy is far away
galaxy further away is travelling faster
observed red shift is greater the further it is
