Topic 8 – Space Physics (Post 2018)

Question 1

Explain why the star is stable while it is in the main sequence stage of its life cycle

Answer 1

gravitational force inwards and forces as a result of fusion reactions outwards
are in equilibrium / balanced

Question 2

Describe what will happen to the star between the main sequence stage and the end of the
star’s life cycle.
You should include the names of the stages in the life cycle of the star.

Answer 2

  (the star will) expand to become a red giant

(the star will) collapse to become a white dwarf
allowed outer layers ejected for collapsed

(the star will) cool to become a black dwarf

Question 3

The term red-shift describes the observed increase
in the ________________________________ of the light from a distant galaxy.

Answer 3

wavelength

Question 4

How does the Big Bang theory describe the universe when it began?

Answer 4

(extremely) hot and dense

Question 5

Describe the relationship between the speed of a galaxy and the distance the galaxy is
from the Earth.

Answer 5

(directly) proportional

Question 6

whats the same as 6 x 10 ^12 terametres?

Answer 6

6 x 10 ^ 24 m

Question 7

Explain how the data in the figure above supports the suggestion that the universe began
from a very small region.

Answer 7

the furthest galaxies are moving the fastest

(this suggests) the universe is expanding (from a very small region)

Question 8

New observations suggest that distant galaxies are moving away from the Earth at an
increasingly fast rate.
What do the new observations suggest is happening to the universe?

Answer 8

expanding at (an ever) greater rate

Question 9

New observations and data that do not fit existing theories should undergo peer review.
Give one reason why peer review is an important process.

Answer 9

• detects false claims
• detects inaccurate data
• detects bias
• verifies new data

*provides a consensus (of opinion)

Question 10

The Andromeda galaxy is moving towards the Earth.
Describe how the wavelength and frequency of the light from Andromeda seem to have
changed when viewed from the Earth.

Answer 10

wavelength (seems to have) decreased

frequency (seems to have) increased

Question 11

A satellite is in a circular orbit around the Earth
Explain why the velocity of the satellite changes as it orbits the Earth

Answer 11

(force of) gravity causes the satellite to accelerate (towards the Earth)

the acceleration causes a change in direction

velocity changes because direction changes

Question 12

A satellite orbits 300 km above the Earth’s surface at a speed of 7.73 km/s.
Calculate how many complete orbits of the Earth the satellite will make in 24 hours.

Answer 12

42 100 = 7.73 × time
time (1 orbit) = 5446(s)
= 15.86
number of orbits = 1

Question 13

The predicted data can be considered to be accurate.
Give the reason why.

Answer 13

the predicted data is very close to the actual data

Question 14

J Bode used his equation to predict the existence of a planet with an orbital radius of 2940
million kilometres.
The planet Uranus was discovered in 1781.
Uranus has an orbital radius of 2875 million kilometres.

Explain why the discovery of Uranus was important.

Answer 14

supported the prediction (made by Bode)

so provides evidence that the equation is true / correct / works / accurate

Question 15

Which one of the following types of electromagnetic wave has the highest frequency?

Answer 15

gamma rays

Question 16

What makes microwaves suitable for sending communications to a satellite in space?

Answer 16

can travel through the atmosphere

Question 17

What event leads to a neutron star forming?

Answer 17

explosion of a red super giant / a supernova

Question 18

When radio waves are absorbed by an aerial they may create an alternating current in an
electrical circuit. If an alternating current is created what frequency would it have?

Answer 18

same as the radio wave

Question 19

The Sun is in the group of main sequence stars. These stars are stable.
Explain why a star remains stable.

Answer 19

expansion due to fusion energy

in equilibrium with

Question 20

At different points in their lifecycle stars change from one group to another.
Describe what will happen to the Sun between it leaving the main sequence group and
becoming a white dwarf.

Answer 20

*   Sun goes from main sequence to red giant
*   then from red giant to white dwarf
*   when the Sun changes to a red giant the surface temperature
will decrease
*   and the relative luminosity will increase
*   when changing from a red giant to a white dwarf the surface
temperature increases
*   and the relative luminosity decreases

Question 21

What provides the force needed to keep a satellite in orbit around the Earth?

Answer 21

gravity

Question 22

Explain how a current is induced in the wire.

Answer 22

as the wire moves through the Earth’s magnetic field

a potential difference is induced between the ends of the wire

the wire must be part of a complete circuit

Question 23

Main sequence star -> Black dwarf is __

Answer 23

Main sequence star, Red giant, White dwarf, Black Dwarf

Question 24

Only stars _____ as the sun become Black dwarfs

Answer 24

same/similar mass

Question 25

In which stage of the life cycle of a star are elements heavier than iron produced?

Answer 25

supernova

Question 26

When scientists observe the light from distant galaxies, they observe an increase in
the ____________of light from those galaxies.

Answer 26

wavelength

Question 27

Write down the equation that links distance travelled (s), speed (v) and time (t).

Answer 27

distance = speed × time

Question 28

Describe the life cycle of stars much more massive than the Sun, including the formation of
new elements.

Answer 28

*   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.

Question 29

Which property of a star does the range of wavelengths depend on?

Answer 29

temperature

Question 30

How does the mean surface temperature of the planets in the table change as the mean
distance from the Sun increases?

Answer 30

it decreases

Question 31

Why is the Moon classified as a satellite?

Answer 31

It orbits a planet.

Question 32

How are planets and moons similar?

Answer 32

Their orbits are circular.

They do not emit visible light.

Question 33

The Sun was formed when a ____________________ in space was pulled
together by ____________________

Answer 33

nebula gravity

Question 34

What stage in the lifecycle of the Sun will follow the Main Sequence stage?

Answer 34

(becomes a) red giant

Question 35

What pattern links the distance a planet is from the Sun and the time taken by the planet to
orbit the Sun?

Answer 35

the greater the distance (from the Sun) the greater the time taken to
orbit the Sun

Question 36

‘The mean surface temperature of a planet decreases the
further the planet is from the Sun.’
Explain why this conclusion is not totally correct

Answer 36

because some planets do not fit the pattern

named planet that does not fit pattern

Question 37

Describe the orbit of an artificial satellite.

Answer 37

circular

Question 38

The star Mira will go through a supernova stage in its lifecycle but the Sun will not.
How is the star Mira different to the Sun?

Answer 38

Mira is much more massive

Question 39

What relationship between the speed of a galaxy and the distance is suggested by
Hubble’s results?

Answer 39

the further away from the Earth, the faster a galaxy is moving

Question 40

a student uses a balloon to model the idea of an expanding Universe.
Some dots, which represent galaxies, were marked on the balloon.
The balloon was then inflated.
Give one strength and one weakness of this model in representing the idea of an
expanding Universe.

Answer 40

strength:
as the balloon expands the dots get further apart, representing the galaxies moving apart

weakness:
dots are only on the surface of the balloon, galaxies are throughout the universe