Space - paper 2

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 name of our galaxy

Answer 2

The milky way

Question 3

How was the sun formed

Answer 3

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 4

What reaction takes places in all stars

Answer 4

Nuclear fusion

Question 5

Why are stars stable?

Answer 5

Fusion reactions lead to an equilibrium between the gravitational collapse of a star and the expansion of a star due to fusion energy.

Question 6

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

Answer 6

1. Nebula or Protostar
2. Main sequence star
3. Red Giant
4. White dwarf
5. Back dwarf

Question 7

Describe the life cycle of a large star

Answer 7

1. Nebula or Protostar
2. Main sequence star
3. Red Super Giant
4. Supernova
5. Neutron star or Black hole

Question 8

Which was the first element created by the big bang

Answer 8

Hydrogen nuclei (protons)

Question 9

How were the light elements made

Answer 9

Fusion in stars

Question 10

How were the heavy elements made

Answer 10

Fusion in supernovas

Question 11

How were all the elements distributed through the universe

Answer 11

By supernovas

Question 12

What forces keeps planets in orbit around a star

Answer 12

Gravity

Question 13

What is a stable orbit?

Answer 13

A stable orbit is one in which the satellite’s 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 14

What is the relationship between orbit radius and speed.

Answer 14

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 15

Define the doppler effect

Answer 15

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

Question 16

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

Answer 16

Wavelength is decreased so frequency is increased

Question 17

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

Answer 17

Wavelength increases so frequency has decreased

Question 18

Define red shift

Answer 18

There is an observed increase in the wavelength and decrease in frequency of light from distant galaxies.

Question 19

What is the relationship between the distance a galaxy is from Earth and thier speed?

Answer 19

The further away the galaxies, the faster they are moving and the bigger the observed increase in wavelength.

Question 20

Define Blue shift

Answer 20

A decrease in wavelength and an increase in freqency as a glaxaxy moves towards an observer.

Question 21

What evidence does red shift provide?

Answer 21

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

Question 22

What is the big bang theory

Answer 22

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

Question 23

Describe the universe before the big bang

Answer 23

Hot and dense

Question 24

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

Answer 24

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 25

How many stars are in our solar system?

Answer 25

One - the sun

Question 26

What are natural satellites?

Answer 26

The moons that orbit planets

Question 27

What type of star is the sun?

Answer 27

A main sequence star

Question 28

How is a red giant formed?

Answer 28

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 29

How is a white dwarf formed?

Answer 29

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