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]

) \% h5 _/ _# F7 p7 ~; W[Specify units of 'J', 'kJ', 'MJ' or 'GJ' in your answer.]
3 A6 _- g3 m9 v5 e/ {+ O: x
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so far what I have done is used the equation for GPE
which is
  x+ b% s9 ~; }+ ZU = - (G me m) / r
6 D$ f$ O5 d" g  D% w; i1 c) q
where G is 6.674e-11 Nmkg-2
$ N" K  }- n8 `2 l, _. ame is the mass of the planet 5.1e24 kg
  ?7 |7 _+ A' \$ t+ N6 D# r4 N# P7 p8 Am is the mass of the space ship 5.9e4 kg
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

chulinlong

做出来了 谢谢

Maths

6 r: s3 M- V& J2 P1 z
' l' b* W0 B7 Q1 c! x0 r用这个公式错了么?
! A7 R2 h  ~3 P还是说只是纯粹的计算出错?

chulinlong

3# Maths
& n4 i* ]: u1 X
! H8 n( F9 C; j3 X# l5 O& ]8 E# @
3 ~5 h5 ^- L  O  L- h: F' ]% H这个公式对的