#P8.3a
explain the red-shift of light as seen from galaxies which are receding (qualitative only). The change with distance of each galaxy’s speed is evidence of an expanding universe
understanding of changes in frequency and wavelength
#P8.3b
explain how red shift and other evidence can be linked to the Big-Bang model
cosmic microwave background radiation
#P8.3c
recall that our Sun was formed from dust and gas drawn together by gravity and explain how this caused fusion reactions, leading to equilibrium between gravitational collapse and expansion due to the energy released during fusion
lifecycle of a star
#P8.3d
explain that all bodies emit radiation, and that the intensity and wavelength distribution of any emission depends on their temperatures
an understanding that hot objects can emit a continuous range of electromagnetic radiation at different energy values and therefore frequencies and wavelengths
#P8.3e
recall the main features of our solar system, including the similarities and distinctions between the planets, their moons, and artificial satellites
the 8 planets and knowledge of minor planets, geostationary and polar orbits for artificial satellites and how these may be similar to or differ from natural satellites
#P8.3f
explain for circular orbits, how the force of gravity can lead to changing velocity of a planet but unchanged speed (qualitative only)
#P8.3g
explain how, for a stable orbit, the radius must change if this speed changes (qualitative only)
#P8.3h
explain how the temperature of a body is related to the balance between incoming radiation absorbed and radiation emitted; illustrate this balance using everyday examples and the example of the factors which determine the temperature of the Earth
an understanding that Earth’s atmosphere affects the electromagnetic radiation from the Sun that passes through it
#P8.3i
explain, in qualitative terms, how the differences in velocity, absorption and reflection between different types of waves in solids and liquids can be used both for detection and for exploration of structures which are hidden from direct observation, notably in the Earth’s core and in deep water
P and S waves, use of sonar