Question

Two satellites A and B go round a planet P in circular orbits having radii 4R and R respectively. If the speed of the satellite A is 3V, the speed of the satellite B will be.

• A. 12 V
• B. 6 V
• C.
• D.

Answer 1

The correct option is B

6 V

$v=\sqrt{\frac{GM}{R}}\Rightarrow \frac{v_A}{v_B}=\sqrt{\frac{R_B}{R_A}}=\sqrt{\frac{R}{4R}}=\frac{1}{2}$
$\therefore \frac{v_A}{v_B}=\frac{3V}{v_B}=\frac{1}{2}\therefore v_B=6V$