Question

One light year is equal to ______.

Answer 1

1. One light-year: It is the distance traveled by the light in one year.
2. As we know in one second light travels 300000 km
   $$\begin{gathered} Thus1lightyear=1year\times speedoflightinonesec \\ \Rightarrow 1lightyear=(365\times 24\times 60\times 60sec)\times (300000km{s}^{-1}) \\ 1lightyear=9.46\times {10}^{12}km \end{gathered}$$
   Hence, One light-year is equal to $9.46\times {10}^{12}km$