A remote sensing satellite of earth revolves in a circular orbit at a height of \(0.25 \times10^6~\text{m}\) above the surface of the earth. If Earth’s radius is \(6.38\times10^6~\text{m}\) and \(g=9.8~\text{ms}^{-2}\), then the orbital speed of the satellite is:
1. \(7.76~\text{kms}^{-1}\)
2. \(8.56~\text{kms}^{-1}\)
3. \(9.13~\text{kms}^{-1}\)
4. \(6.67~\text{kms}^{-1}\)
A satellite \(S\) is moving in an elliptical orbit around the earth. If the mass of the satellite is very small as compared to the mass of the earth, then:
1. | The angular momentum of \(S\) about the centre of the earth changes in direction, but its magnitude remains constant. |
2. | The total mechanical energy of \(S\) varies periodically with time. |
3. | The linear momentum of \(S\) remains constant in magnitude. |
4. | The acceleration of \(S\) is always directed towards the centre of the earth. |
1. | \(v_o=v_e\) | 2. | \(v_e=\sqrt{2v_o}\) |
3. | \(v_e=\sqrt{2}~v_o\) | 4. | \(v_o=\sqrt{2}~v_e\) |