8.1 SOLAR SYSTEM Flashcards
How many planets make up our solar
system?
Eight (plus the dwarf planets).
What do the planets in our solar system
orbit around and what type of body is it?
● The planets orbit around the sun
● The sun is a star
What type of force pulled together the
cloud of dust and gas to form the Sun?
Gravitational force of attraction.
What word is used to describe a cloud of
dust and gas?
A nebula.
What type of reactions take place at the
start of a star’s life cycle as dust and gas
is drawn together?
Fusion reactions.
What factor determines the type of
lifecycle a star undergoes?
The size of the star.
Which two phases do all stars of the
same or greater size than the sun
undergo?
- Protostar phase
2. Main sequence phase
What do stars of a similar magnitude to
the sun become at the end of their
life-cycle?
A black dwarf.
What two things can stars much bigger
than the sun become at the end of their
lifecycle?
- Neutron star
2. Black hole
What two phases do stars of similar size
to the sun go through between being a
main sequence star and a black dwarf?
- Red giant
2. White dwarf
What two phases do stars of greater size
than the sun go through between being a
main sequence star and a neutron
star/black hole?
- Red super giant
2. Supernova
What are produced during the fusion
processes in a star?
All of the naturally occurring elements.
What condition is required for fusion
reactions to occur in a star?
Very high temperatures.
How are elements heavier than iron
produced?
In a supernova.
What type of nuclei fuse 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
supernova
What allows planets and satellites to
maintain circular orbits?
● Gravity provides the gravitational force
that acts as the object’s centripetal force
● The presence of a centripetal force
allows for the object to maintain its
circular orbit
What type of satellite can a planet’s
moon be described as?
A natural satellite.
Give two examples of artificial satellites.
- TV satellites
2. 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 a 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 alter its velocity since the
direction is continually changing
● It can’t cause a change of speed since
there is no force component in the direction
of motion
