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Calculate the energy required to move an earth satellite of mass `10^(3)` kg from a circular orbit of radius 2R to that of radius 3R. Given mass of the earth,`M=5.98xx10^(24)` kg and radius of the earth, `R=6.37xx10^(6)`m. |
Answer» Given M = 5.98 x 1024 kg m = 103 kg R = 6.37 x 106 m Centripetal acceleration of the satellite is provided by the gravitational force exerted by Earth. \(\frac{mv^2}{r}=\frac{GMm}{r^2}\) v2 = GM/r Total energy of the system = K.E. + Gravitational Potential energy = 1/2 mv2 - GMm/r = 1/2 m GM/r - GMm/r = - 1/2 GMm/r Therefore, energy required to move on Earth satellite radius 2R to orbital radius 3R. E = GMm/2 (1/2R - 1/3R) E = GMm/12R \(E=\frac{6.67\times10^{-11}\times5.98\times10^{24}\times10^3}{12\times6.37\times10^6}\) \(E=\frac{39.88\times10^{10}}{76.44}\) ⇒ 0.5217 x 1010 J Correct Answer - `5.02xx10^(9)`J |
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