InterviewSolution
| 1. |
i)Derive an expression for critical velocityof satellite. |
|
Answer» Consider a satellite of mass m revolving round the Earth at a, height 'h' above the surface of the Earth. Let M be the mass and R be the radius of the Earth. The satellite is moving with velocity V and the radius of the circular orbit isr=R+hr=R+h. Centripetal force = Gravitational force ∴Mv2cr=GMmr2∴Mvc2r=GMmr2 ∴v2c=GMr∴vc2=GMr ∴vc=√GMR+h∴vc=GMR+h This is the expression for critical velocity of a satellite moving in a circular orbit around the Earth, We know that, gh=GM(R+h)2gh=GM(R+h)2 GM=gh(R+h)2GM=gh(R+h)2 Substituting in equation (1), we get ∴vc=√gh(R+h)2R+h∴vc=gh(R+h)2R+h ∴vc=√gh(R+h)∴vc=gh(R+h) whereghghis the acceleration due to gravity at a height above the surface of the Earth. |
|