Paper 2 - Space

Question 1

Describe our solar system

Answer 1

the Sun, plus the eight planets and the dwarf planets that orbit around the Sun. Natural satellites, the moons that orbit planets, are also part of the solar system.

Question 2

State the planets in order from the closest to the sun outwards

Answer 2

Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune

Question 3

How many stars are in our solar system?

Answer 3

One - the sun

Question 4

State the name of our galaxy

Answer 4

The milky way

Question 5

How was the sun formed

Answer 5

The Sun was formed from a cloud of dust and gas (nebula) pulled together by gravitational attraction. This cloud heats up until fusion can start.

Question 6

What reaction takes places in all stars

Answer 6

Nuclear fusion

Question 7

Why are stars stable?

Answer 7

Nuclear fusion reactions lead to an equilibrium between the gravitational collapse of a star and the expansion of a star due to fusion energy (radiation pressure).

Question 8

Describe the life cycle of a small star, like the sun

Answer 8

Nebula, Protostar, Main sequence star, Red Giant, White dwarf, Black dwarf

Question 9

Describe the life cycle of a large star

Answer 9

Nebula, Protostar, Main sequence star, Red Super Giant, Supernova, Neutron star or Black hole

Question 10

Which was the first element created by the big bang

Answer 10

Hydrogen nuclei (protons)

Question 11

How is a red giant formed?

Answer 11

Hydrogen runs out and the star initially collapses as gravity is now the stronger force. After a star collapses, the star heats up enough for helium to fuse and it expands (radiation pressure > gravity)

Question 12

What type of star is the sun?

Answer 12

A main sequence star

Question 13

How is a white dwarf formed?

Answer 13

The red giant starts to run out of its fuel (Helium) Gravity is bigger than radiation pressure so the star collapses

Question 14

How were the light elements made

Answer 14

Fusion in stars

Question 15

How were the heavy elements made

Answer 15

Fusion in supernovas

Question 16

How were all the elements distributed through the universe

Answer 16

By supernovas

Question 17

Define the doppler effect

Answer 17

The change in frequency of a wave, caused by relative motion between the source of the wave and the observer

Question 18

Why is the pitch lower when a car is moving away from you?

Answer 18

Wavelength increases so frequency has decreased

Question 19

Why is the pitch higher when a car is moving towards you?

Answer 19

Wavelength is decreased so frequency is increased

Question 20

Define red shift

Answer 20

There is an observed increase in the wavelength of light from most distant galaxies. The further away the galaxies, the faster they are moving and the bigger the observed increase in wavelength.

Question 21

What evidence does red shift provide?

Answer 21

The observed red-shift provides evidence that space itself (the universe) is expanding and supports the Big Bang theory.

Question 22

The further the galaxy is away from us, the ? Recessional velocity?

Answer 22

Greater

Question 23

What is the big bang theory

Answer 23

The Big Bang theory suggests that the universe began from a very small region that was extremely hot and dense.

Question 24

What additional evidence supports the big bang theory?

Answer 24

The CMBR (cosmic microwave background radiation)

Question 25

What is dark matter?

Answer 25

Matter that interacts with gravity but cannot be seen (does not emit electromagnetic waves)

Question 26

Why do scientists think there is dark matter?

Answer 26

To explain the increase in rotational velocity or sprial galaxies towards the edges

Question 27

What is dark energy?

Answer 27

Energy that increases the rate of the expansion of the universe

Question 28

Why do scientists there is dark energy?

Answer 28

As the rate of expansion of the universe seems to be increasing

Question 29

What is the relationship between orbit radius and speed.

Answer 29

The gravitational attraction between two objects decreases with distance. This means that the closer the two objects are to each other, the stronger the force of gravity between them. This means that objects in small orbits travel faster than objects in large orbits. In order to change orbital speed, an object must change the radius of its orbit at the same time, to maintain a stable orbit.

Question 30

What are natural satellites?

Answer 30

The moons that orbit planets

Question 31

What forces keeps planets in orbit around a star

Answer 31

Gravity

Question 32

What is a stable orbit?

Answer 32

A stable orbit is one in which the satellites speed is just right - it will not fly off into space (too fast) or spiral into the Earth (too slow) but will travel around a fixed path.

Question 33

What do we call any force that acts towards the centre of a circle?

Answer 33

Centripetal force

Question 34

How can an object in orbit be travelling at a constant speed but still be accelerating

Answer 34

the object is constantly changing direction,so the velocity must be changing. A change in velocity is an acceleration. The object is always accelerating towards the centre of the orbit

Question 35

How can you calculate the circumfrence of an orbit?

Answer 35

2 x pi x radius