Question

The radius of the earth is about 6371 kilometers. The radius of the moon is about 1737 kilometers. What ratio is closest to the ratio of the circumference of the moon to the circumference of earth?

Answer 1

11:40

Explanation:

First, we need to calculate the circumference of both.

The circumference of a circular object can be calculated as 2πr

The circumference of the earth is thus 2 * 3.142 * 6371 = 40,030 = approximately 40,000Km

The circumference of the moon = 2 * 3.142 * 1737 = 10,913 = apprx 11,000

The ratio of the circumference of the moon to that of the earth is 11,000:40,000 = 11:40

Answer 2

1.1 : 4.

Explanation:

Given:

rmoon = 1737 km

rearth = 6371 km

Circumference of a circle, C = 2pi × r

Cearth = 2pi × 6371

= 4.0 × 10^7 m

Cmoon = 2pi × 1737

= 1.1 × 10^7 m

Ratio of Cmoon to Cearth

= 1.1 × 10^7 : 4.0 × 10^7

= 1.1 : 4.