Question

How far can light travel in a year?A. 100 milesB. 1 million milesC. 6 billion miles

Answer 1

Explanation:

the speed of the light is

$v=3\times10^8\text{ m/s}$

the time in a year is

$\begin{gathered} t=365\text{ days}\times24\text{ hours}\times60\text{ minutes}\times60\text{ seconds} \\ \end{gathered}$

the distance traveled by the light is

$d=v\text{ t}$

Plugging all the values in the above relation, we get

$\begin{gathered} d=365\times24\times60\times60\text{ s}\times3\times10^8\text{ m/s} \\ d=946080\times10^{10}\text{ m} \end{gathered}$

now convert this into miles.

$1\text{ m=0.000621 miles}$

now the distance is,

$\begin{gathered} d=946080\times0.000621\times10^{10}\text{ miles} \\ d=587.51\times10^{10}\text{ miles} \\ d=\text{ 6 billion miles} \end{gathered}$

Thus, the distance traveled by the light in a year is 6 billion.