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]
2 _8 ^5 I& H0 t7 t" I% X% p6 k
6 k0 [5 ^7 w4 N  i* o4 y[Specify units of 'J', 'kJ', 'MJ' or 'GJ' in your answer.]
+ A4 R! O" z1 q* u* N+ ?9 c
* Q: b! H7 X" K! G/ C% w
! `4 L+ n) _5 g$ k( K# f$ ^; uso far what I have done is used the equation for GPE
which is
U = - (G me m) / r

3 }) S1 M. W* d; f' {where G is 6.674e-11 Nmkg-2
me is the mass of the planet 5.1e24 kg
$ ^! Q. @' o6 `2 a( H' D: t: zm is the mass of the space ship 5.9e4 kg
7 i; |* l: N6 S+ C3 R9 Fr 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

) G+ p7 _% G7 ]0 y! o, ~
用这个公式错了么?
还是说只是纯粹的计算出错?

chulinlong

3# Maths
  W# F4 I) O3 N6 v' I' X2 J
3 S7 _5 O* c  x4 J2 w5 l2 T
& u5 s7 R+ h# g5 @这个公式对的