Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Edexcel GCSE Physics (9-1) > SP7 - Astronomy ✓ > Flashcards

SP7 - Astronomy ✓ Flashcards

1
Q

SP7a - What developments in techonology have allowed us to make more detailed observations?

A
  • Computers allow detailed analysis.
  • Photography allows accurate and permanent storage of events.
  • Telescopes can now be place outside of the earth’s atmosphere giving wider and more detailed detection.
  • Space probes allow better analysis of the solar system.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

SP7a - What is the geocentric model?

A

The model of our solar system in which everything orbits the earth.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

SP7a - What is the heliocentric model?

A

The current model of our solar system where the sun is at the centre and other planes orbit it.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

SP7a - Who came up with Geocentric Model?

A
  • Ptolemy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

SP7a - Who came up with Heliocentric Model?

A

Copernicus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

SP7a - Why are telescopes place outside the earth’s atmosphere more detailed than a regular telescope?

A
  • The earth’s atmosphere absorbs many waves of the EM spectrum.
  • Outside the atmosphere, these could be detected. (such as infrared radiation)
  • Clouds and dust in the air do not interfere with the image
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

SP7a - What shape is the earth’s orbit around the sun?

A

Elliptical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

SP7b - A satellite in which type of orbit is used for communication with parts of the earth near the poles?

A

Highly elliptical orbits

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

SP7b - A satellite in which type of orbit needs the least fuel for launching?

A

Low earth orbits

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

SP7b - A satellite in which type of orbit will eventually pass over all parts of the earth?

A

Polar orbits

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

SP7b - At what angle is the force between the earth and satellite?

A

90°

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

SP7b - Explain the speeds that a satellite would have to be travelling at in relation to its orbit, and the changes in orbit it would experience if it changed speed.

A
  • The gravitational force on an object in a lower orbit is a stronger than at a higher orbit so a satellite at a lower orbit would have to travel at a higher speed to stay in orbit.
  • Once it eventually slows down, it will drop towards earth.
  • However as it drops it gains speed and will eventually be able to be at a lower orbit at a faster speed.
  • Once it drops enough that it passes through the earth’s atmosphere, the air resistance will slow it down and it will eventually fall to earth.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

SP7b - What are the four types of orbits for artificial satellites?

A
  • Highly elliptical
  • Circular geostationary
  • Low earth orbits
  • Polar orbits
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

SP7b - What is a geostationary orbit and what are these satellites used for?

A
  • Satellites that stay in the same place relative to the earth’s position.
  • They move at 3070 m/s and are used for broadcasting.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

SP7b - What is the difference between weight and mass?

A

Your weight is the force acting on you dependant on your mass and the gravitational field strength. Whereas, mass is a measure of the amount of material in an object.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

SP7b - What is the gravitational field strength on earth?

A

9.81 N/Kg

(Can be rounded to 10N/Kg)

17
Q

SP7b - What reaction takes place inside a star?

A

Nuclear fusion

(typically H + H = He)

18
Q

SP7b - Why doesn’t a satellite continue moving in a straight line?

A

The gravitational force between the earth and the satellite causes it to continuously change direction and orbit the earth.

19
Q

SP7b - Describe the life cycle of a star much larger than our sun. [6 Marks]

A
  • It starts with a Nebula (A cloud of gas and gases).
  • The materials are pulled together by their own gravity, becoming denser until their own gravtitational pull causes it to collapse in on itself forming a protostar.
  • Eventually the pressure and temperature in the protostar become large enough that nuclear fusion starts to occur converting hydrogen to helium
  • The energy released form the fusion reactions push the star outward causing it to expand.
  • Once the force of the gravity pulling the star inwards matches the force of pressure from the fusion reactions, the star will be at a steady size and in its main sequence stage where it continues to convert hydrogen to helium
  • Eventually, hydrogen runs out and heavier reactions take place.
  • This creates more energy which expands the star more forming a red supergiant.
  • These heavier fusions are carried out all the way to iron when it runs out of fuel.
  • The star rapidly collapses causing a supernova
  • This leaves behind a very dense neutron star
  • If the mass of the star is even larger, then a black hole is formed in place of the neutron star.
20
Q

SP7b - Describe the life cycle of a star the size of our sun. [6 Marks]

(write this down)

A
  • It starts with a Nebula (A cloud of gas).
  • The particles in this pull themselves together, becoming denser until their own gravity causes it to collapse in on itself forming a protostar.
  • Eventually the pressure and temperature in the protostar become large enough that nuclear fusion starts to occur converting hydrogen to helium
  • The energy released form the fusion reactions push the star outward causing it to expand.
  • Once the force of the gravity pulling the star inwards matches the force of pressure from the fusion reactions, the star will be at a steady size and in its main sequence stage where it continues to convert hydrogen to helium
  • Eventually, hydrogen runs out and heavier reactions take place.
  • This creates more energy which expands the star more
  • The outermost layers are no longer held in place by the force of gravity so they expand forming a red giant
  • Once all the fuel has run out, all the layers disband forming a shell of gas.
  • This leaves behind a highly dense white dwarf which doesn’t carry out any reactions.
21
Q

SP7d - What do we use to check red-shift?

A

Absorption spectrums of the galaxy compared to the absorption spectrum of the sun.

22
Q

SP7d - What does it mean if one galaxy has a greater red-shift than another?

A

That galaxy is further away and moving faster than the other.

23
Q

SP7d - What is red-shift?

A

When light form distant galaxies shift towards the red side of the spectrum due to wavelengths being stretched as the galaxy moves away from earth.

24
Q

SP7d - What is the doppler effect?

A

When the pitch of a noise get lower as it travels aways from you. (and higher when it travels towards you)

25
Q

SP7d - Why does the doppler effect occur?

A

As a sound travels, the wavelengths are squashed or stretched meaning the sound’s pitch appears higher or lower.

26
Q

SP7e - What are the two main theories for the origin of the universe?

A
  • The big bang theory
  • Steady state theory
27
Q

SP7e - What can we use as a model of why CMBR proves The Big Bang Theory?

A
  • A Currant bun has currants close together.
  • As the dough rises, the number of currants stay the same but they are found at consistent rate throughout the bun.
28
Q

SP7e - What is the Big Bang Theory?

A
  • This theory states that the Universe began 13.8 billion years as a tiny particles and expanded from that point and is still expanding today.
29
Q

SP7e - What is the Steady State Theory?

A
  • The universe always existed and as it expands as matter is continuosly created.
30
Q

SP7e - What provides evidence for both theories of the universe and why?

A

Red-shift; as galaxies are constantly moving away the universe is constantly expanding.

31
Q

SP7e - What provides evidence for the currently accepted theory?

A

It is thought that gamma radiation was released in the Big Bang.

Due to the expanding universe, the wavelength of this radiation has increased, resulting in the microwave radiation present today

32
Q

SP7e - Which theory of the universe is the currently accepted theory?

A

The Big Bang Theory

Edexcel GCSE Physics (9-1) (17 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions