P16 - Space 2️⃣✅

Question 1

What is the big bang theory?

Answer 1

The theory that the universe was created in a massive explosion, and that the universe has been expanding ever since

Question 2

What is a black dwarf?

Answer 2

A star that has faded out and has gone cold

Question 3

What is a black hole?

Answer 3

An object in space that has so much mass that nothing, not even light, can escape from its gravitational field

Question 4

What is centrepedal force?

Answer 4

The resultant force towards the centre of a circle acting on an object moving in a circular path; it acts perpendicular to the direction of forward motion

Question 5

What is a main sequence star?

Answer 5

A star that has reached the stage in its life cycle during which it radiates energy because of the nuclear fusion of hyrogen to heium in its nucleus

Question 6

What is a neutron star?

Answer 6

The highly compressed core of a massive star that remains after a supernova explosion

Question 7

What is a protostar?

Answer 7

The concentration of dust clouds and gas in space that forms an early star

Question 8

What is a red giant?

Answer 8

A star that has expanded and cooled, resulting in it becoming red and much larger and cooler than it was before it expanded

Question 9

What is a red supergiant?

Answer 9

A star significantly larger than the sun expanding and cooling and becoming what is essentially a red giant, but due to its siginificantly larger size, its known as a red supergiant

Question 10

What is the Mnemonic for the planets in our solar sytem in order?

Answer 10

My
Very
Easy
Method
Just
Speeds
Up
Naming
(Planets)

Question 11

What are the planets of a solar system in order?

Answer 11

Mercury
Venus
Earth
Mars
Jupiter
Saturn
Uranus
Neptune
(Pluto)

Question 12

What are planets?

Answer 12

Planets are large rocky objects that orbit around a star (planets in our solar system orbit a star (the sun))

Question 13

What are exoplanets?

Answer 13

Planets that orbit another star that isnt our sun

Question 14

What is a comet?

Answer 14

A small cosmic snowball of frozen gasses, rock & dust that orbit the sun in an elliptical orbit (ellipse = squashed circle) - when it comes closer to the sun it heats up and the ice starts to melt (hence shooting stars)

Question 15

What is an asteriod?

Answer 15

Floating lumps of rock

Question 16

What is a metiorite?

Answer 16

An asterioid that has entered an atmosphere

Question 17

What is a geostationary satelite?

Answer 17

A satelite that orbits at the same speed as the earth’s orbit so it will always be at the same place overhead

Question 18

What is geosynchronous orbit?

Answer 18

When an object in orbit passes over the same spot the same time everyday as the orbit takes roughly 24 hours.

Question 19

Why do weather satelites have a very low orbit?

Answer 19

So they orbit at quicker speeds

Question 20

What is low polar orbit?

Answer 20

A ‘vertical’ orbit from the north to the south pole

Question 21

What is a satelite?

Answer 21

A smaller object orbiting a larger object

Question 22

What are the two most common types of orbits?

Answer 22

Circular & Elliptical orbits

Question 23

What is instantanious velocity?

Answer 23

Velocity at one instant in time that is always perpendicular to the direction of force

Question 24

What is a natural satelite?

Answer 24

A natural satellite is any body in space that orbits around a larger body

Question 25

What is an artificial satelite?

Answer 25

An artificial satellite is a man-made body placed in orbit round the earth or another planet, commonly in order to collect information about it or for communication purposes

Question 26

Complete this diagram for the life cycle of a star

Answer 26

Question 27

What is a white dwarf?

Answer 27

White dwarfs are the remnants of averaged sized stars stars that have exhausted all of their nuclear fuel and have collapsed under their own gravity. They are incredibly dense, with a mass similar to that of the sun but a size comparable to that of Earth

Question 28

What does an average main sequence star do to produce energy?

Answer 28

Undergo nuclear fuision of hydrogen atoms into helium which releases unfathamable ammounts of energy, significantly larger than nuclear fission

Question 29

What happens when a star runs out of hydrogen atoms to fuse?

Answer 29

Fusion will stop and therefore the outwards pressure force the fusion produces also stops, rendering the balance between the outwards pressure force and inwards gravitational force unbalanced, causing the star to collapse inwards under gravitys inwards force. The increased pressure because of this will cause the star to become even denser and hotter, causing the helium atoms to fuse and produce elements like carbon. This reinistates the outwards pressure force due to fusuion reoccuring and resulting in the star expanding, forming a red giant

Question 30

How are elements upto Iron produced?

Answer 30

For stars larger than the sun, after carbon, they will continue to fuse elements larger than the previous up until iron. When they reach iron, so much energy is produced in the core of the star that it causes a massive explosion - a supernova where enormous ammounts of heat and light energy are released.

Question 31

How are the elements above Iron produced?

Answer 31

During the supernova explosion

Question 32

What happens to a red supergiant after a supernova?

Answer 32

Depending on the size, it will become a neutron star (if smaller) but if siginifcantly larger star it will become a black hole

Question 33

What will a red giant eventually become?

Answer 33

A white dwarf and then after 10s/100s of billions of years become a black dwarf

Question 34

What are the forces that act on a star?

Answer 34

The force of gravity acts inwards towards the star whereas the energy/ pressure produced by the star’s nuclear fusion produced an outwards force, equal to the gravity, therefore leaving the star in balance

Question 35

Why are low polar orbits used for spying?

Answer 35

Because they are lower, they produce higher quality images and can move quicker

Question 36

How does red-shift imply/ support the big bang theory?

Answer 36

As red-shift insinuates that the universe its expanding in the present day, it is therefore implied that the universe was once small and at some point, tiny

Question 37

What is red-shift?

Answer 37

It is a result of the space between the Earth and the galaxies expanding. This expansion stretches out the light waves during their journey to us, shifting them towards the red end of the spectrum. The more red shifted the light from a galaxy is, the faster the galaxy is moving away from Earth

Question 38

What are 2 proposed theories for the origins of the universe?

Answer 38

• Big bang theory
• Steady state theory

Question 39

What is the steady state theory?

Answer 39

Theory before the big bang that proposes that the universe is being pushed apart by matter that is being created to counteract its loss in density

Question 40

What are 2 pieces of evidence to suppor the big bang theory?

Answer 40

• Red shift
• Cosmic microwave background information

Question 41

What is cosmic microwave background radiation?

Answer 41

The accidental discovery of the cold remannts of the immense levles of radiation that would have been emitted during the big b bang; the radiation, originally would have been much larger and hotter, but over the years its cooled down into microwaves