Time period relation for inverse n-th power gravity – Rankers Physics
Topic: Gravitation
Subtopic: Newton's Law of Gravitation

Time period relation for inverse n-th power gravity

Suppose the gravitational force varies inversely as the \(n^{\text{th}}\) power of distance. Then, the time period of a planet in circular orbit of radius \(R\) around the sun will be proportional to
\(R^n\)
\(R^{\frac{n+1}{2}}\)
\(R^{\frac{n-1}{2}}\)
\(R^{-n}\)

Solution:

The centripetal force is provided by the gravitational force: \(m \omega^2 R = \frac{k}{R^n} ⇒ \omega^2 \propto \frac{1}{R^{n+1}}\). Since \(T = \frac{2\pi}{\omega}\), we get \(T^2 \propto R^{n+1} ⇒ T \propto R^{\frac{n+1}{2}}\).

Leave a Reply

Your email address will not be published. Required fields are marked *