Space Physics

Question 1

Which Galaxy is our Solar System part of?

Answer 1

Milky Way Galaxy

Question 2

How many planets are in our solar system?

Answer 2

8 planets (plus the dwarfs plants)

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 which 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 is a nebula?

Answer 5

a cloud of gas and dust

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

• protostar phase
• main sequence phase

Question 9

What do stars of a similar magnitude to the sun become at the end of their lifecycle?

Answer 9

A black dwarf

Question 10

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

Answer 10

neutron star, 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

red giant, 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

Red super giant-> Supernova

Question 13

What are the produced during the fusion processes in a star?

Answer 13

all naturally occurring elements

Question 14

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

Answer 14

very high temperatures

Question 15

How are elements heavier than ions produced?

Answer 15

In a supernova

Question 16

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

Answer 16

Hydrogen nuclei fuse to form heavier elements.

Question 17

How are elements distributed throughout the universe?

Answer 17

Through the explosion of a massive star (supernova).

Question 18

What allows planets and satellites to maintain circular orbits?

Answer 18

● 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

Question 19

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

Answer 19

natural satellite

Question 20

Give two examples of artificial satellites

Answer 20

TV satellites
Satellites used for satellite imaging

Question 21

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

Answer 21

● 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 22

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

Answer 22

● 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

Question 23

What is red shift?

Answer 23

An observed increase in the wavelength of light from distant galaxies.

Question 24

What two things can be said about the motion and wavelength of emitted light from a galaxy, the further away it is?

Answer 24

● The further away a galaxy is, the faster it is moving
● The further away a galaxy is, the greater the observed increase in wavelength

Question 25

What does red-shift provide evidence for?

Answer 25

● Provides evidence that the universe is expanding
● Supports the Big Bang theory

Question 26

What does the Big Bang theory suggest?

Answer 26

The entire universe started from a very small, hot and dense region in space.

Question 27

Compare the observed red-shift of two galaxies, one further away than the other.

Answer 27

● The galaxy that is further away is travelling faster
● The observed red-shift is greater the further away it is

Question 28

What did scientists observe to provide evidence that the universe is expanding at an ever faster rate?

Answer 28

They observed supernovae, which suggested that galaxies are moving away at an ever faster rate.

Question 29

Prior to observations of supernovae, what was believed about the rate of expansion of the universe and why?

Answer 29

● The rate of expansion was expected to occur at an ever slower rate
● It was thought that gravitational forces would cause this slowing down

Question 30

What two ideas could explain the universe’s ever increasing rate of expansion?

Answer 30

● The existence of energy and mass that we can’t detect, known as dark matter and dark energy
● These ideas are still being developed by scientists