A particular emission spectral line is measured in the laboratory to have a frequency of $7.3\times {10}^{14} \mathrm{Hz}$. Calculate the wavelength of this spectral line in the laboratory.

A particular emission spectral line is measured in the laboratory to have a frequency of $7.3\times {10}^{14} \mathrm{Hz}$.

(b) Calculate the observed wavelength of this same spectral line in the spectrum of a galaxy moving away from the Earth at a speed of:

(i) $11{\mathrm{Mms}}^{-1}$

A particular emission spectral line is measured in the laboratory to have a frequency of $7.3\times {10}^{14} \mathrm{Hz}$. Calculate the observed wavelength of this same spectral line in the spectrum of a galaxy moving away from the Earth at a speed of $7.0\%$ the speed of light.

A particular emission spectral line is measured in the laboratory to have a frequency of $7.3\times {10}^{14} \mathrm{Hz}$. The spectrum of all distant galaxies is redshifted. State and explain what you can deduce about the Universe.

The recession speed $v$ against distance $d$ graph for some galaxies is shown.

Determine the Hubble constant from this graph. Explain your answer.

The Big Bang occurred some 14 billion years ago.

$1 \text{years} \approx 3.15\times {10}^{-7}\mathrm{s}$

Estimate the farthest distance we can observe. Explain your answer.