Topic 12Physics (Edexcel)

Astrophysics and Cosmology

Astrophysics and Cosmology — Edexcel International A-Level Physics (Unit 5). Covers: Gravitational Fields; Stars and Stellar Radiation; Cosmology.

1

Gravitational FieldsSign up

understand that a gravitational field (force field) is defined as a region where a mass experiences a force · understand that gravitational field strength is defined as g = F/m and be able to use this equation · be able to use the equation F = G m1 m2 / r^2 (Newton's law of universal gravitation) · be able to derive and use the equation g = Gm/r^2 for the gravitational field due to a point mass · be able to use the equation Vgrav = -Gm/r for a radial gravitational field · be able to compare electric fields with gravitational fields · be able to apply Newton's laws of motion and universal gravitation to orbital motion

40 min
2

Stars and Stellar RadiationSign up

understand what is meant by a black body radiator and be able to interpret radiation curves for such a radiator · be able to use the Stefan-Boltzmann law equation L = sigma A T^4 for black body radiators · be able to use Wien's law equation lambda_max T = 2.898 x 10^-3 m K for black body radiators · be able to use the equation, intensity I = L / (4 pi d^2) where L is luminosity and d is distance from the source · understand how astronomical distances can be determined using trigonometric parallax · understand how astronomical distances can be determined using measurements of intensity received from standard candles (objects of known luminosity) · be able to sketch and interpret a simple Hertzsprung-Russell diagram that relates stellar luminosity to surface temperature · understand how to relate the Hertzsprung-Russell diagram to the life cycle of stars

40 min
3

CosmologySign up

understand how the movement of a source of waves relative to an observer/detector gives rise to a shift in frequency (Doppler effect) · be able to use the equations for redshift z = lambda/lambda ≈ f/f ≈ v/c for a source of electromagnetic radiation moving relative to an observer and v = H0 d for objects at cosmological distances · understand the controversy over the age and ultimate fate of the universe associated with the value of the Hubble constant and the possible existence of dark matter.

40 min
Astrophysics and Cosmology | A2 Physics (Edexcel) · Find Tutor