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]
1 `: p  X+ ~9 u8 C) _
[Specify units of 'J', 'kJ', 'MJ' or 'GJ' in your answer.]


* W; H; K) x- Tso far what I have done is used the equation for GPE
# i" q9 d7 W+ r2 |which is
2 t1 N) X$ H8 c; v  P6 xU = - (G me m) / r
0 Y  X- S1 i+ g& O4 c
6 y, e% k) f2 _" C& ^9 J& Qwhere G is 6.674e-11 Nmkg-2
+ C4 a& |8 H4 H% g, c( R/ }me is the mass of the planet 5.1e24 kg
; R4 a$ _; b6 c, `& }8 lm 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

' R; z, C  P" g* ?. N; o5 v) m$ r! j
8 X6 d2 k9 u$ @  f. g# |: k用这个公式错了么?
# v% `# N4 e# G: @  m! P* e+ I# H还是说只是纯粹的计算出错?

chulinlong

3# Maths
* @: }9 a6 s! Q# _6 n# O

6 x( L  F4 _, |- r# b0 V# I这个公式对的