It is estimated that light takes 10,000 years to travel the full distance across our galaxy. If light travels at 3.0 x 10^8m in 1 second then what is the distance across the milky way? Give your answer in standard form



Answer :

Given:
Time taken = 10,000 years
Now,
converting 10,000 years to seconds,
We have,
1 year = 365 days
          = (365 * 24) hours
          = (365 * 24 * 60) minutes
          = (365 * 24 * 60 * 60) seconds
          = 31536000 seconds
So,
Time taken = 10,000 years = (10000 * 31536000 seconds)
                                        = [tex]3.1536 * 10^{11} seconds[/tex]
Also, according to the question,
speed = [tex]3.0* 10^{8} m[/tex]

We know,
speed = distance / time taken
speed * time taken = distance
[tex](3.0* 10^{8}) *3.1536 * 10^{11} = distance[/tex]
[tex]9.4608* 10^{19} = distance[/tex]
 
So, the distance across the milky way is [tex]9.4608* 10^{19}[/tex] meters.
AL2006
In standard form and units of my choosing, the distance is 10,000 light-years.