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]
- w, X9 r, }) ?
[Specify units of 'J', 'kJ', 'MJ' or 'GJ' in your answer.]


so far what I have done is used the equation for GPE
$ A0 |$ h, ^# p" Qwhich is
0 U8 p$ t; M: a, T, l3 }1 r% SU = - (G me m) / r
6 l) n; n, u+ A) X& N- q! [, G) }) a9 ^. i
8 F, d- t9 F9 ?where G is 6.674e-11 Nmkg-2
me is the mass of the planet 5.1e24 kg
* x# x( `  D) e1 \( um 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

* Q# U: c  v' \( s1 A+ @0 D# L, Q
* f" T( o& A4 H5 ^. ?' s) p/ l: ~用这个公式错了么?
还是说只是纯粹的计算出错?

chulinlong

3# Maths

2 T1 e" V9 j; c5 g3 @5 g; Q. y% t
这个公式对的