Q. 5

# Two satellites A and B move round the earth in the same orbit. The mass of B is twice the mass of A.

A. Speeds of A and B are equal.

B. The potential energy of earth + A is same as that of earth + B.

C. The kinetic energy of A and B are equal.

D. The total energy of earth + A is same as that of earth + B.

Answer :

Let the mass of Earth be M and the radius of the orbit be r. The velocity of satellite in an orbit is given by . As the speed is independent of the mass of the satellites, (a) is true.

The potential energy of the system is given by which depends on the masses of the satellite. Hence (b) is false.

The kinetic energy is which also depends on the mass of satellites. So, (c) is false.

The total energy is sum of KE and PE. As both depend on the mass of satellite, the total energy also depends on it and (d) is false.

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