Booklet 1B - Cosmology (Equations)

Question 1

(Define symbols and units)

Answer 1

F - Gravitational Force (N)

G - Universal Constant of Gravitation (see data sheet - m³kg^-1s^-2)

m - mass (kg)

r - distance between centres of objects (m)

Question 2

(Define symbols and units)

Answer 2

t’ - dilated time (s) observed in a different frame of reference

t - proper time (s) observed in the same frame of reference

v - relative velocity (ms^-1)

c - speed of light (ms^-1)

Question 3

(Define symbols and units)

Answer 3

l’ - contracted length (m) observed in a different frame of reference

l - proper length (m) observed in the same frame of reference

v - relative velocity (ms^-1)

c - speed of light (ms^-1)

Question 4

(Define symbols and units)

Answer 4

f_o - observed frequency (Hz)

f_s - frequency of source (Hz)

v - speed of wave (ms^-1)

v_s - relative speed of source (ms^-1)

Question 5

(Define symbols and units)

Answer 5

z - Redshift (no unit)

λ_observed - observed wavelength (m)

λ_rest - stationary wavelength (m)

Question 6

(Define symbols and units)

Answer 6

z - Redshift (no unit)

v - relative speed of source (ms^-1)

c - speed of light (ms^-1)

Question 7

(Define symbols and units)

Answer 7

v - speed of recession of galaxy (ms^-1)

H_o - Hubble Constant (see data sheet - s^-1)

d - distance to galaxy (m)