Space

Question 1

Black Body Radiators?

Answer 1

Perfect absorbers and emitters of EM waves

Question 2

Relationship between the peak wavelength and the absolute temperature?

Answer 2

Wien’s Law
λ(max) * T = 2.898x10^-3

Question 3

The relationship relating the luminosity (power output) to the temperature and surface area?

Answer 3

Stefan-Botzmann Law
L= σAT^4
σ = 5.67x10^-8

Question 4

What is the luminosity of a star?

Answer 4

The power of its emission or the amount of energy emitted per second

Question 5

What is an AU?

Answer 5

Astronomical unit
Distance between Earth’s Centre and Sun’s Centre
Measures distances in the solar system
1.5x10^11m

Question 6

What is a light year?

Answer 6

Distance travelled by light in a year
63000AU
1x10^ 16

Question 7

What is trigonometric paralax?

Answer 7

Using the distance between the earth and the sun to measure the distance to a nearby star

Question 8

What is a parsec?

Answer 8

the angle of the parallax is 1/3600
1arcsecond
3.09x10^16m

Question 9

How can you estimate the luminosity of a star using its intensity and distance?

Answer 9

I = L/4πd^2 and L = 4πr^2σT^4

Question 10

What is a standard candle?

Answer 10

An object in space with known luminosity

Question 11

How can you use standard candles to measure distance?

Answer 11

Using the inverse square law I = L/4πd^2

Question 12

What diagram shows the types of stars?

Answer 12

HR diagram - Luminosity against surface area

Question 13

The formation of stars?

Answer 13

Dust left from supernovae comes together becoming very hot and dense
Causes a protostar
Protostar heats up until it reaches millions of degrees and the hydrogen nuclei fuse
Nuclear fusion releases energy and creates enough energy to overcome gravitational collapse

Question 14

What happens to main sequence stars?

Answer 14

Pressure-balanced gravity for the majority of life
Fuses all hydrogen so pressure decreases
Star collapses on itself and the core heats up to fuse helium while the extremities become cooler
This is a red giant

Question 15

What happens to low-mass stars?

Answer 15

They eventually become white dwarfs

Question 16

What happens to high-mass stars?

Answer 16

They die more quickly and then supernova leaving a neutron star of black whole

Question 17

What’s the doppler effect?

Answer 17

The motion of a wave’s source effects the observed frequency

Question 18

Blueshift?

Answer 18

Object approaches us so observed f is higher

Question 19

Redshift?

Answer 19

Object is moving away so observed f is lower

Question 20

What does redshift show?

Answer 20

The universe is expanding at an ever-increasing rate

Question 21

Relationship between the distance away from us and the velocity of the galaxy?

Answer 21

v = H(0)d
H is Hubble’s constant
They are directly proportional

Question 22

How was the Hubble constant found?

Answer 22

Using standard candles to find the recessional velocity and ten plotting it against the distance

Question 23

What is the Hot Big Bang Theory?

Answer 23

The universe started as a very goit and very dense singularity and has been ever-expanding since

Question 24

What is the controversy with H(0)

Answer 24

No one knows H(0) so you cant calculate the age of the universe

Question 25

What is the fate of the universe?

Answer 25

Depending on the mass of the universe and therefore it’s density (causing gravity)
The universe will either crunch or expand for ever

Question 26

What’s an arcminute?

Answer 26

1/60 degrees

Question 27

What’s an arc second?

Answer 27

The measurement for angles of parallax
1/3600

Question 28

How would you find the speed of an object using the Doppler effect?

Answer 28

Δ λ / λ = -v / c
Or

Δf / f = v / c

Question 29

What is dark matter?

Answer 29

Matter that doesn’t interact with EM spectrum

Question 30

Why don’t we know date of the universe?

Answer 30

H(o) unknown
Dark matter quantity unknown