# If the average distance of a planet from the sun is 1.8 AU, find out its orbital period? (answer...

## Question:

If the average distance of a planet from the sun is 1.8 AU, find out its orbital period?

(answer should be in years)

## Orbital Period:

The orbital period of a planet can be evaluated by examining the average distance of this planet from the sum. The value of the orbital period varies linearly to the amount of the average distance from the sun. The mass of the planet does not affect it.

## Answer and Explanation:

Given data:

• The average distance of a planet from the sun, {eq}a = 1.8\;{\rm{AU}} {/eq}

By using Keplers third law calculate the orbital period,

{eq}{P^2} = {a^3} {/eq}

Substitute the values,

{eq}\begin{align*} {P^2} &= {\left( {1.8} \right)^3}\\ {P^2} &= 5.832\\ P &= 2.41\;{\rm{years}} \end{align*} {/eq}

Therefore, the orbital period is {eq}2.41\;{\rm{years}} {/eq} .

#### Learn more about this topic:

Kepler's Three Laws of Planetary Motion

from Basics of Astronomy

Chapter 22 / Lesson 12
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