Question

An artificial satellite $(mass=M)$ of earth revolves in a circular orbit whose radius is $4$ times the radius of the earth. Assume that in the spherical region between the radius $4R_e$ and $2R_e$, there is cosmic dust. If mass of the satellite is increasing at the rate of $u$ per sec. Find the time in which satellite will come to orbit of radius $2R_e$.

• A. $\frac{M}{u}(\sqrt{3}-1)$.
• B. $\frac{M}{u}(\sqrt{2}-1)$.
• C. $\frac{M}{u}(\sqrt{4}-1)$.
• D. $\frac{M}{u}(\sqrt{6}-1)$.

Answer 1

The correct option is B $\frac{M}{u}(\sqrt{2}-1)$.