Two satellites of earth, S₁ and S₂ are moving in the same orbit. The mass of S₁ is four times the mass of S₂. Which one of the following statements is true?

Options

(a) The potential energies of earth satellites in the two cases are equal
(b) S₁ and S₂ are moving with the same speed
(c) The kinetic energies of the two satellites are equal
(d) The time period of S₁ is four times that of S₂

Correct Answer:

S₁ and S₂ are moving with the same speed

Explanation:

Since, orbital velocity of satellite is
v = √(GM / r), it does not depend upon the mass of the satellite.
Therefore, both satellites will move with same speed.