Planet and Satellite: Practice Problem & Solution
A satellite of mass \(m\) is in a circular orbit of radius \(2R\) about the earth. How much energy is required to transfer it to a circular orbit of radius \(4R\) : (\(R =\) Radius of earth)
Solution Explained:
To solve this problem, we apply the core principles of Planet and Satellite. Understanding the underlying formula is key to arriving at the correct answer below:
The total energy of a satellite is \(E = -\frac{GMm}{2r}\). The required energy is \(\Delta E = E_f - E_i = -\frac{GMm}{8R} - \left(-\frac{GMm}{4R}\right) = \frac{GMm}{8R}\). Since \(g = \frac{GM}{R^2}\), we get \(\Delta E = \frac{mgR}{8}\).
Leave a Reply