8.1 Solar System

Question 1

which galaxy is our solar system part of?

Answer 1

the milky way galaxy.

Question 2

how many planets make up our solar system?

Answer 2

eight (plus the dwarf planets).

Question 2

what do the planets in our solar system orbit around and what type of body is it?

Answer 2

• the planets orbit around the sun
• the sun is a star

Question 3

what word is used to describe a cloud of dust and gas?

Answer 3

a nebula.

Question 3

what type of force pulled togther the cloud of dust and gas to form the sun?

Answer 3

gravitational force of attraction.

Question 4

what type of reactions take place at the start of a star’s life cycle as dust and gas is drawn together?

Answer 4

fusion reactions.

Question 4

what factor determines the type of lifecycle a star undergoes?

Answer 4

the size of the star.

Question 5

which two phases do all starts of the same or greater size than the sun undergo?

Answer 5

1. protostar phase
2. main sequence phase

Question 6

what do stars of a similar magnitude to the sun become at the end of their life-cycle?

Answer 6

a black dwarf.

Question 7

what two things can stars much bigger than the sun become at the end of their lifecycle?

Answer 7

1. neutron star
2. black hole

Question 8

what two phases do stars of similar size to the sun go through between being a main sequence star and a black dwarf?

Answer 8

1. red giant
2. white dwarf

Question 8

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?

Answer 8

1. red super giant
2. supernova

Question 9

what are produced during the fusion processes in a star?

Answer 9

all of the naturally occurring elements.

Question 10

what condition is required for fusion reactions to occur in a star?

Answer 10

very high temperatures.

Question 10

how are elements heavier than iron produced?

Answer 10

in a supernova.

Question 11

what type of nuclei fuse together to form heavier elements in a star?

Answer 11

hydrogen nuclei fuse to form heavier elements.

Question 11

how are elements distributed throughout the universe?

Answer 11

through the explosion of a massive star (supernova).

Question 12

what allows planets and satellites to maintain circular orbits?

Answer 12

• gravity provides the gravitational force that acts as the object’s centripetial force
• the presence of a centripetal force allows for the object to maintain its circular orbit

Question 13

what type of satellite can a planet’s moon be described as?

Answer 13

a natural satellite.

Question 13

give two examples of articial satellites.

Answer 13

1. tv satellites
2. satellies used for satellite imaging

Question 13

explain why for a stable orbit, the radius of orbit must change if the speed changes.

Answer 13

• 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

Question 14

explain how the force of gravity acting on a satellite affects its speed and velocity.

Answer 14

• the force can alter its velocity sinnce the direction is continually changing
• it can’t cause a change of speed since there is no force component in the direction of motion