Topic 8 Space Physics

Question 1

Nebulas

Answer 1

How stars initially form and is a cloud of dust and gas

Question 2

Protostars

Answer 2

The gravity pulls the dust together to form a protostar. The star gets denser and so does the temperature when the temperature gets high enough hydrogen nuclei undergo nuclear fusion to form helium nuclei giving huge amounts of energy

Question 3

Main sequence stars

Answer 3

A long stable period when the outward pressure caused by nuclear fusion balances with the force of gravity pushing inwards and lasts for several billion years

Question 4

Red super giants and red giants

Answer 4

When the hydrogen runs out the star swells to a red super giant or red giant and it becomes red as it is cooler.

Question 5

White dwarfs

Answer 5

Small to medium sized star become unstable and eject its outer layer of dust and gas. Leaving a hot dense solid core

Question 6

Black dwarfs

Answer 6

A white dwarf cools down emitting less energy once it no longer emits a significant amount of energy it becomes a black dwarf

Question 7

Supernovas

Answer 7

Big stars will glow brightly as fusion increases and expand and contract and eventually explode forming elements heavier then iron these form new plants and stars

Question 8

Neutron stars and black holes

Answer 8

The exploding supernova throws the outer layers of dust and gas into space leaving a dense core called a neutron star or if it is big enough it will become a black hole

Question 9

The cycle of a small star

Answer 9

Cloud of dust and gas- main sequence star- red giant- white dwarf- black dwarf

Question 10

The cycle of a bigger star

Answer 10

Cloud of dust and gas- protostar- main sequence star- red super giant- supernova- neutron star or black hole

Question 11

Planets

Answer 11

Large objects that orbit a sun. Have to be large enough to “clear their neighbourhood” so they pull in any nearby objects apart from natural satellites

Question 12

Dwarf planets

Answer 12

Planet like objects that orbit the sun but don’t meet all the rules for being a planet

Question 13

Moons

Answer 13

Orbit planets and a type of natural satellite

Question 14

Artificial satellites

Answer 14

Satellites that were created by humans

Question 15

The size of the orbit depends on the objects speed

Answer 15

The closer to a planet the stronger the gravitational force. The stronger the force the faster it has to travel to stay in orbit. In a stable orbit if the speed changes so does the size of the object. Faster objects will have a smaller radius of their orbit

Question 16

Gravity creating orbits

Answer 16

Constantly changing direction so velocity as well. The force is directed towards the centre. It keeps accelerating towards what is circling it but the instantaneous velocity Keeps it travelling in a circle

Question 17

The red-shift the expanding universe

Answer 17

Light from the most distant galaxies have an increased wavelength. So the wavelength has moved to the red end of the spectrum suggesting the source is moving further away

Question 18

Suggesting the universe started with the Big Bang

Answer 18

Initially the universe occupied a small area so was dense and hot. Then it exploded causing an expansion and it is still going on

Question 19

New evidence which could change theories

Answer 19

The Big Bang is the best theory at this point in time. Observations of the 1998 supernova show distant galaxies are moving away faster and faster. The universe is thought to be made of dark matter and dark energy these are thought to be responsible for the expansion of the universe