Calculating C for a Freely Falling Satellite

[didimimi2266]

Homework Statement

A satellite falls freely towards the Earth starting from rest at distance R, much larger than the Earth's radius.Treating the Earth as a point mass M then
T=C(R^3/GM)^0.5
where G is gravitational constant
By using equation of motion of the satellite, show that C=pi/2^(1.5)

Homework Equations

use GM/r^2=a

The Attempt at a Solution

I m not sure how the satellite falls ...why is pi in the constant C??

 

[ideasrule]

What's T supposed to be?

 

[didimimi2266]

What's T supposed to be?

Sorry..T is the time taken by the satellite to reach the Earth