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]
' [6 O/ O! `) `0 J* }: D7 K% f7 C
[Specify units of 'J', 'kJ', 'MJ' or 'GJ' in your answer.]
7 f. M( ]; X8 V3 Q! B) G3 K0 A

; X3 q* n1 j) b6 K) o1 t, W8 Dso far what I have done is used the equation for GPE
) E8 c" b- m; f) R- Ywhich is
% G+ |+ z' C. Y1 B* d% UU = - (G me m) / r
8 R0 `" n5 }, P# ^+ e' `$ y
where G is 6.674e-11 Nmkg-2
8 r" G6 U  i) }3 Q$ ?7 S  Mme is the mass of the planet 5.1e24 kg
1 p5 v+ h) y/ S) l! t3 D+ d  p% gm is the mass of the space ship 5.9e4 kg
6 u0 }1 O* d# ?! H2 Q( ?1 Q" sr 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

% D& H5 A! K# `" _用这个公式错了么?
还是说只是纯粹的计算出错?

chulinlong

3# Maths

5 x: O1 s9 r: m5 _
这个公式对的