8.1 Space physics (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 3

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

Answer 3

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

Question 4

What type of force pulled together the cloud of dust and gas to form the sun?

Answer 4

gravitational force of attraction

Question 5

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

Answer 5

a nebula

Question 6

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

Answer 6

fusion reactions

Question 7

What factor determines the type of lifecycle a star undergoes?

Answer 7

the size of the star

Question 8

Which two phases do all stars of the same or greater size than the sun undergo?

Answer 8

1. Protostar phase
2. Main sequence phase

Question 9

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

Answer 9

A black dwarf

Question 10

What two things can stars much bigger than the sun become at the end of their life cycle?

Answer 10

1. Neutron star
2. Black hole

Question 11

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

Answer 11

1. Red giant
2. White dwarf

Question 12

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 12

1. Red super giant
2. Supernova

Question 13

What are produced during the fusion processes in a star?

Answer 13

all of the naturally occurring elements

Question 14

What are the naturally occurring elements?

Answer 14

all of the elements on the periodic table

Question 15

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

Answer 15

very high temperatures

Question 16

How are elements heavier than iron produced?

Answer 16

in a supernova

Question 17

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

Answer 17

hydrogen nuclei fuse to form heavier elements

Question 18

How are elements distributed throughout the universe?

Answer 18

through the explosion of a massive star (supernova)

Question 19

What allows planets and satellites to maintain circular orbits?

Answer 19

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

Question 20

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

Answer 20

a natural satellite

Question 21

Give two examples of artificial satellites

Answer 21

1. TV satellites
2. Satellites used for satellite imaging

Question 22

Explain why for a stable orbit, the radius of orbit must change if the speed changes?

Answer 22

• 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 23

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

Answer 23

• 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