IIT JEE , AIEEE Forum - Physics , Mechanics - gravitation [admin]:apply Keplar's third lawfor inverse force

chinmay_kothekar

Hi

Keplar's third law states that T²=R³ then prove that it is applicable for any inverse force i.e for any Rⁿ.

cvramana

Let the force be F = k / Rⁿ ------------------(1)

Therefore

M w² R = k / Rⁿ ---------------(2)

Therefore T² is proportional to R^{n +}¹

If n =2 we get Kepler's Third law.

chinmay_kothekar

Hi

I didnt understand the last step

if Mw²R = k/Rⁿ, then how is T²

R³

cvramana

It is not T² proportional to R³

But

It is T² proportional to R^{n + 1}

Since the force is F = k / Rⁿ