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A space craft of mass 5.9×104 kg is in orbit around a planet of 5.1×1024 kg. If the planet can be assumed to be a uniform sphere of radius 5.4×106 m and the space ship is orbit a height of 6.9×105 m above the surface what is the gravitational potential energy of the ship? [G=6.674×10-11 Nm2kg-2]% D# |3 f& K, p/ w! D
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[Specify units of 'J', 'kJ', 'MJ' or 'GJ' in your answer.]
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so far what I have done is used the equation for GPE
6 \% U1 v: j0 | c+ Ywhich is
% ~7 i; c% Q1 G y1 OU = - (G me m) / r! p. H$ ]( R" I+ M
x7 V. \0 \% R( }$ `4 ?
where G is 6.674e-11 Nmkg-2' C' j8 ~9 t! q/ y1 E+ G
me is the mass of the planet 5.1e24 kg # O8 b8 K0 N1 s
m is the mass of the space ship 5.9e4 kg N k% l, ?9 N% e
r is (i think) the radius of the planet (5.4e4 m) added to the height of the space ship is above the planet (6.9e5 m) and then divided it into G me m |
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发表于 2009-11-10 21:41
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' k" b- N; x9 M2 `. a/ R