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]
( ~3 v$ w" b. R4 r) D
, D5 g( w' _# d% G[Specify units of 'J', 'kJ', 'MJ' or 'GJ' in your answer.]


so far what I have done is used the equation for GPE
which is
8 G! I* h" }. f' i+ `: hU = - (G me m) / r
/ h6 X* ^. ^' ]4 A. _) O, I
) x0 Z/ _; A* L2 y2 F/ w) o9 Lwhere 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
/ }& M4 \- d5 |; R$ V) _# g4 E+ Vr 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

) z, H; D2 E% X/ s3 k, T% o7 u* A
  r4 X) e" a1 x; [6 _5 \用这个公式错了么?
还是说只是纯粹的计算出错?

chulinlong

3# Maths

1 I0 k$ `( Q( B% I6 x$ n! H- j" A2 n
这个公式对的