求 一道物理题 12点前

chulinlong

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]
$ ]( @% S. z4 z
' j$ t  @/ f) I  Z; g1 v& v[Specify units of 'J', 'kJ', 'MJ' or 'GJ' in your answer.]
9 {- [$ t# w4 [1 p# W6 X

so far what I have done is used the equation for GPE
which is
) Q" _- b7 Z0 a) }U = - (G me m) / r

where G is 6.674e-11 Nmkg-2
me is the mass of the planet 5.1e24 kg
m is the mass of the space ship 5.9e4 kg
5 \2 i" R! M7 h0 p( E/ E* wr 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

chulinlong

做出来了 谢谢

Maths

6 z' S" k2 X. }) W- |/ n  i2 J用这个公式错了么?
+ W5 b! j3 K! s% _. v- Y* A还是说只是纯粹的计算出错?

chulinlong

3# Maths
8 b  c* K1 l9 S3 p/ J% Y! D; q
" @) y- Z5 N0 R8 T
, r% J: P! G( U0 F这个公式对的