# Kinematics - Uniform Circular Motion

#### nahanksh

1. Homework Statement
What is the period, T, of the satellite's orbit (G is the gravitational constant, 6.7 × 10-11 m3 kg-1 s-2) ?
(The picture is attached)http://online.physics.uiuc.edu/cgi/courses/shell/common/showme.pl?courses/phys211/oldexams/exam1/sp08/fig18.gif [Broken]

2. Homework Equations
a = w^2*r
w=2pi/period
F = -Gm1m2/(R^2)

3. The Attempt at a Solution

Using the force equation and "a=F/m",

I got a = GMe/Rs^2

And using a = w^2*Rs,

GMe/Rs^2 = w^2*Rs

Then, the angular velocity keeps having Rs^3 which doesn't seem to be right when compared to the answer...

What's wrong with my attempt?

The answer should be "T= 2*pi*Rs/sqrt(GMe)

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#### cepheid

Staff Emeritus
Gold Member
The answer should be "T= 2*pi*Rs/sqrt(GMe)

No, T should definitely be proportional to R3/2, that's where Kepler's Third Law comes from.

#### nahanksh

Oh, so you think what i was doing was right..?

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