Question

Energy required to move a body of mass $m$ from an orbit of radius $2R$ to $3R$ is:

• A. $\frac{GMm}{6R}$
• B. $\frac{GMm}{R}$
• C. $\frac{GMm}{8R}$
• D. $\frac{GMm}{2R}$

Answer 1

Answer: (A)

Energy required $=($ Final potential-Initial potential $)m$
Energy required $=-\frac{GMm}{3R}-\frac{-GMm}{2R}=\frac{GMm}{6R}$