Express 1light year in terms of meters. What is its order of magnitude.

 $$\begin{gathered} Speed of light c=3\times {10}^{8}m/s \\ Time for one year t=1year = 365\times 24\times 60\times 60 \hspace{0.17em} Second \\ dis\tan ce travelled by light in a year=ct=3\times {10}^8\times 365\times 24\times 60\times 60 \\ 1 light year=0.9467\times {10}^{16} \\ Order of magnitude = 16 \end{gathered}$$