| Date | November 2010 | Marks available | 3 | Reference code | 10N.3.HL.TZ0.E2 |
| Level | Higher level | Paper | Paper 3 | Time zone | Time zone 0 |
| Command term | Explain | Question number | E2 | Adapted from | N/A |
Question
This question is about the Big Bang model and red-shift.
Many galaxies are a great distance from Earth. Explain, with reference to Hubble’s law, how the measurement of the red-shift of light from such galaxies enables their distance from Earth to be determined.
State one problem associated with using Hubble’s law to determine the distance of a galaxy a great distance from earth.
Markscheme
the amount of red-shift enables the recession speed of a galaxy to be determined;
Hubble’s law states that the recession speed is proportional to its distance from Earth/ \(v = {H_0}d\) with terms defined;
if the constant of proportionality/ \({H_0}\) is known then d can be determined;
it is difficult to determine an accurate value of the Hubble constant / difficult to measure the red-shift / Hubble constant had different values in the past;
Examiners report
Too many candidates lost marks by not defining the symbols in the Hubble Law.
Part (d) was usually answered correctly.
