Solutions

Final test: Edexcel Core - Waves in the Earth and Universe P1.3 P1.4 (15 marks)

  1. Continental drift is caused by sea floor spreading. Which is the best description of sea floor spreading? (circle the correct answer)
  1. Earthquakes under the sea bed causing the land to move.
  2. Hot mantle rising causing plates to pull apart.
  3. Shrinking of the Earth's crust allowing oceans to form between continents.
  4. Tectonic plates pushing against each other.

(1 mark)

  1. The diagram shows earthquake waves arriving at a seismometer.

P S

Write a letter P on the diagram to show the part showing the P wave arriving and a letter S to show the

S wave. Both correct for 1 mark

(1 mark)

  1. Stars that are much bigger than the sun expand then shrink throughout their life. Describe the stages massive stars go through when most of their Hydrogen is used up.
  • Massive stars form red super-giants
  • These often explode as a supernova
  • This explosion can lead to the formation of a neutron star or a black hole

(4 marks)

3. The spectra below show light from the sun and two other galaxies.

Violet Red

Sun

Galaxy A

Galaxy B

What do the spectra show and what does this tell you about the two galaxies?

  • The spectra show redshift of the two galaxies when compared to the sun
  • Both galaxies must be moving away from us
  • Galaxy B is moving faster and so is further away

(3 marks)

4. QWC: Light from distant galaxies is re-shifted. Explain why this red-shift occurs and what it tells us about the

movement of these galaxies.

QWC Suggested marking guidance (Total 6 marks)
Marks awarded for this answer will be determined by the Quality of Written Communication (QWC) as well as the standard of the scientific response. Teachers should and apply a ‘best-fit’ approach to the marking.
0 marks / Level 1 (1-2 marks) / Level 2 (3-4 marks) / Level 3 (5-6 marks)
No relevant content. / An attempt at an explanation of redshift with 1 -2 marking points.
The spelling, punctuation and grammar are very weak. / A brief explanation of redshift with 3-4 marking points.
There is reasonable accuracy in spelling, punctuation and grammar, although there may still be some errors / A clear explanation of redshift with all marking points.
The answer shows almost faultless spelling, punctuation and grammar.
  • Stars emit light of all wavelengths.
  • If a galaxy is moving away from us
  • The wavelength of emitted light is stretched
  • Red light has the longest wavelength of visible light
  • All galaxies have different amounts of red-shift
  • So they must all be moving away from us
  • At different velocities

(6 marks)

1

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