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Grade 12th passMechanics

The average distance of the sun from the earth is 390 times the average distance of the moon from the earth .Now consider a total eclipse of the sun (Moon between earth and sun and calculate (a)the ratio of the sun's diameter to the Moon's diameter.(b)the ratio of the sun's volume to the Moon's volume.?

Profile image of FAZAL RAHIM SHAH
7 Years agoGrade 12th pass
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1 Answer

Profile image of Askiitians Tutor Team
ApprovedApproved Tutor Answer1 Year ago

To tackle this question, we need to understand the relationships between the distances and sizes of the Sun, Earth, and Moon. The average distance from the Earth to the Sun is about 93 million miles (or approximately 150 million kilometers), while the average distance from the Earth to the Moon is about 238,855 miles (or about 384,400 kilometers). Given that the average distance of the Sun from the Earth is 390 times that of the Moon, we can use this information to derive the ratios you’re interested in.

Calculating the Ratios

Let's break this down step by step.

1. Ratio of the Sun's Diameter to the Moon's Diameter

The average diameter of the Sun is about 1,391,000 kilometers, while the average diameter of the Moon is about 3,474 kilometers. To find the ratio of the Sun's diameter to the Moon's diameter, we can use the following formula:

  • Sun's Diameter: 1,391,000 km
  • Moon's Diameter: 3,474 km

Now, we calculate the ratio:

Ratio = Sun's Diameter / Moon's Diameter

Ratio = 1,391,000 km / 3,474 km ≈ 400.5

This means the Sun's diameter is approximately 400.5 times that of the Moon's diameter.

2. Ratio of the Sun's Volume to the Moon's Volume

To find the volume ratio, we need to use the formula for the volume of a sphere, which is:

Volume = (4/3)πr³

First, we need to find the radii of the Sun and Moon:

  • Sun's Radius: 695,500 km
  • Moon's Radius: 1,737 km

Now we can calculate the volumes:

Volume of the Sun = (4/3)π(695,500 km)³

Volume of the Moon = (4/3)π(1,737 km)³

To find the ratio of the volumes:

Volume Ratio = Volume of the Sun / Volume of the Moon

Since the (4/3)π cancels out, we can simplify this to:

Volume Ratio = (Sun's Radius³) / (Moon's Radius³)

Substituting the values:

Volume Ratio = (695,500 km)³ / (1,737 km)³

Calculating this gives:

Volume Ratio ≈ (695,500 / 1,737)³ ≈ (400.5)³ ≈ 64,000,000

This indicates that the Sun's volume is approximately 64 million times greater than that of the Moon.

Summary of Findings

In summary, we found:

  • The ratio of the Sun's diameter to the Moon's diameter is approximately 400.5:1.
  • The ratio of the Sun's volume to the Moon's volume is about 64,000,000:1.

These calculations highlight the vast differences in size between the Sun and the Moon, which is crucial for understanding phenomena like solar eclipses. The immense size of the Sun compared to the Moon is what allows for such a dramatic effect during a total eclipse, despite the Moon being much closer to Earth.