Question

Scientists discovered a large star 250,000 light-years from Earth. A light-year

is about 5,880,000,000,000 miles. What is the distance of the large star from
Earth in scientific notation?

Answer 1

Answer: OPTION B

Explanation:

Scientific notation has the form:

`a10^n`

Where "a" is a number between 1 and 10 but is not less than 10 and "n" is an integer.

If a light-year is about 5,880,000,000,000 miles and the large star is 250,000 light-years from Earth, then this distance in miles is:

`d=(250,000)(5,880,000,000,000)\\d=1,470,000,000,000,000,000.0\ mi`

To express this distance in scientific notation, the decimal point must be after the first digit. You can observe that the decimal point must be moved 18 places, then:

`a=1.47` and
`n=18`

Therefore, you get that the distance of the large star from Earth in scientific notation is:

`d=1.47*10^(18)\ mi`

Answer 2

B. 1.47*10^18

Explanation:

Given

Distance of largest start from earth in light years = 250000

1 light year = 5880000000000 miles

So,

Distance of largest star from earth in miles = 250000 * 5880000000000

= 1470000000000000000 miles

In order to convert in scientific notation, point will be moved 18 places to the left, so the number will become:

1.47* 10^18 miles

So option B is correct..