- Home
- Standard 11
- Physics
A satellite $S$ is moving in an elliptical orbit around the earth. The mass of the satellite is very small compared to the mass of the earth. Then
the acceleration of $S$ is always directed towards the centre of the earth
the angular momentum of $S$ about the centre of the earth changes in direction, but its magnitude remains constant
the total mechanical energy of $S$ varies periodically with time
the linear momentum of $S$ remains constant in magnitude
Solution

Force on satellite is always directed towards earth, So, acceleration of satellite $S$ is always directed towards centre of earth. Net torque of this gravitational force $F$ about centre of earth is zero. Therefore , angular momentum (both in magnitude and direction) of $S$ about centre of earth is constant throughout. Since, the force $F$ is conservative in nature, therefore, mechanical energy of satellite remains constant. Speed of $S$ is maximum when it is nearest to earth and minimum when it is farthest.