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28 votes
28 votes
what fraction of the Earth's surface would be covered by the surface of the moon,if the radius of the Earth is 6,378km and the radius of the moon is 1.741km?​

User Dalya
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1 Answer

10 votes
10 votes

Answer:

3031081 / 40678884

Explanation:

To solve this, we can find the surface area of the moon and Earth, and then see how much the moon covers the Earth. The surface area of a sphere is equal to 4πr², so the radius of the Earth is

4πr² = 4 * π * 6378²

and the radius of the moon is

4πr² = 4 * π * 1741²

To figure out how much of the Earth's surface that the moon covers, we can implement a ratio of moons:Earth. This will give us an understanding of how many moons go inside one Earth. We thus have

(4 * π * 1741²) : ( 4 * π * 6378²) = (4 * π * 1741²) / ( 4 * π * 6378²)

cross out the 4 * π in the numerator and denominator

1741²/6378²

Next, we want to make the denominator 1, as that gives us 1 Earth. To do this, we can divide both the numerator and denominator by 6378². Because we are applying the same expression to both the numerator and denominator, this is essentially multiplying the fraction by 1, keeping it the same. We thus have

(1741²/6378²)/(6378²/6378²)

≈0.0745/1

≈ 0.0745

To put this in a fraction, we would have

(1741²/6378²)/1

= (1741²/6378²)

= 3031081 / 40678884

User Rbaskam
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2.7k points