Period of a Simple Pendulum with Varying Masses and Gravitational Forces

[rbwang1225]

Homework Statement

The usual formula for the period T of a simple pendulum of length l is T=2[itex]\pi[/itex][itex]\sqrt{\frac{l}{g}}[/itex] where g is the acceleration due to gravity. Denoting rhe inertial mass of the pendulum bob by m[itex]_{i}[/itex] and its gravitational mass by m[itex]_{g}[/itex], derive an alternative expression for T in terms of these masses, the radius R of the Earth and its mass M[itex]_{g}[/itex].

Homework Equations

The Attempt at a Solution

I just replaced g as [itex]\frac{GM_{g} {m_{g}}}{R^{2}m_{i}}[/itex].
I don't know if this is what the author wants.

 

[BruceW]

That looks correct to me.