Question

A light-year is a unit used to measure large distances in space. One light-year is approximately equal to 5.88 trillion miles. On a map of the Milky Way Galaxy, the scale is 1 inch:70 light-years. If two stars on the map are 19 inches apart, about how far apart are they in the galaxy?

Answer 1

`7.8204* 10^(15)\ \text{miles}`

Explanation:

In the map the scale is

`1\ \text{inch}=70\ \text{light-years}`

So

`19\ \text{inches}=19* 70=1330\ \text{light-years}`

In miles

`1\ \text{light-year}=5.88* 10^(12)\ \text{mi}`

`1330\ \text{light-years}=1330* 5.88* 10^(12)=7.8204* 10^(15)\ \text{miles}`

The galaxies are
`7.8204* 10^(15)\ \text{miles}` apart.