Physics Space Flashcards
The sun is the only star in the
solar system
There are how many planets in our solar system
8
What type of celestial body is a moon?
natural satellite
Formation of the sun steps
- Cloud of gas and dust (a nebula) collapsed due to gravity
- This formed a protostar which continued to accumulate more mass
- The temperature and pressure became high enough for nuclear fusion to start
- The star then went into a stable period called a main sequence star
In the Sun, what process creates a force outwards, balancing the inward force of gravity?
Nuclear fusion
The Sun is
currently ————–
and is powered by nuclear ———–
and is a ———– ————– star
stable
fusion
main sequence
weight with units equations =
weight in newtons
mass (kg) * gravitational field strength N/kg
comets and asteroids are balls of
which orbit the
ice and rock which also orbit the sun
If the speed of the object in orbit changes then the
the radius of the orbit also changes.
If the radius of the orbit increases then the
This explains why planets closer to the sun travel at a faster speed.
the speed decreases as the gravitational attraction is smaller.
What happens when the radius of an object in orbit decreases?
speed increases
What happens when the radius of an object in orbit decreases?
it speeds up
In a main sequence star, ——————are fused together to form ——.
This releases energy as ——-and ——.
hydrogen nuclei
heluim
heat
light
Red giant formation
Eventually all the hydrogen fuel runs out.
The star then cools and expands, becoming a red giant.
The star then starts to fuse together helium nuclei to release energy.
It is formed when he outward force of the energy is larger than the inward force of gravity so the star expands.
White dwarf process
As the heluim fuel runs out in a small to meduim star like the sun then the, the outward forces reduce in size and the star collapses inwards ejecting its outer layer of gas and dust.
This causes is temperatures to increase. A white dwarf is formed which is the hot core of the star.
Black dwarf very short summary
when the stars completely cools it becomes a black dwarf.
A black dwarf doesn’t emit any light or heat
How does a star become a super red giant quick summary
Nuclear fusion changes more and more of the star’s mass into energy. The star expands into a red super giant
Supernova quick summary (about how its created) what does it produce?
the largest stars explode into supernovas. A supernova produces elements heavy than iron and scatters them throughout the universe.
Black holes and neutrons stars are formed
by a supernova
Life Cycle of a large star
Fusion (processes in stars) produce new elements
Cloud of gas / hydrogen and dust OR nebula
Pulled together by gravity
Causing increasing temperature (to start the fusion process)
(To become a) protostar
Hydrogen nuclei fuse to form helium nuclei
And the star becomes main sequence
Hydrogen begins to run out
Helium nuclei fuse to make heavier elements
Up to iron
The star expands (to become a)
Red super giant
(The star collapses rapidly) and explodes
Called a supernova
Creating elements heavier than iron
And distributing them throughout the universe
Leaving behind a neutron star
Or a black hole
All stars fuse ——– nuclei into ——- in nuclear ———
hydrogen
helium
fusion
Larger stars fuse —— nuclei into ——- and other ———
heluim
lithium
of light metals
Describe red shift and explain how it supports the big bang theory as an explanation for how the universe began
(6 marker)
Red shift is when the wavelengths of observed light from a source are longer than that of the light emitted from the source. This occurs when the source of the light emitted by the source is moving away from the observer.
The light from the most distant galaxies is observed to be red-shifted. The light from galaxies that are further away from us is more redshifted than the light from nearer galaxies. This inidcates that all of these glaxies are moving away fromand each other. This suggests that the universe is expanding. The Big Bang theory is the theory that the universe began as a small region of space that was very hot and dense which exploded and his been expanding ever since. Therefore the observations of red-shift support the idea of the origin of the universe suggested by the BIG BANG THEORY
Evidence for an expanding universe
Light from distant galaxies in space is red-shifted. The further a galaxy is from earth, the Greater the red shift. This means that the further away a galaxy is, the faster it is moving away from us.
