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]
$ c- f9 n- @# i1 {( b0 V& Q! {
0 r: s, x' i* K) p[Specify units of 'J', 'kJ', 'MJ' or 'GJ' in your answer.]


" [* _/ p* Y) V: r) e5 nso far what I have done is used the equation for GPE
- ~! W) \/ E: qwhich is
U = - (G me m) / r
5 X& P( I! i/ D# A
where G is 6.674e-11 Nmkg-2
1 y8 s; r  _% \7 }; f1 tme is the mass of the planet 5.1e24 kg
m is the mass of the space ship 5.9e4 kg
1 F4 J) p8 r# A% j: Ar 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

8 ^, l4 ^# E- \% r3 e
2 T( N  ?! Y9 `$ u# v# d% L用这个公式错了么?
还是说只是纯粹的计算出错?

chulinlong

3# Maths

! e& M8 h; |6 j3 E3 b
这个公式对的