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]

[Specify units of 'J', 'kJ', 'MJ' or 'GJ' in your answer.]
6 G8 D0 \9 l& n8 P, V

. g  V2 ?- S- n+ }2 D# p/ e  M6 Dso far what I have done is used the equation for GPE
1 h2 C& f: {- c5 p$ L" A) Mwhich is
U = - (G me m) / r

3 j5 L& x4 k* R& `! A+ P) _/ vwhere G is 6.674e-11 Nmkg-2
$ m3 F* x+ @2 U) W' n) c; Mme is the mass of the planet 5.1e24 kg
m is the mass of the space ship 5.9e4 kg
6 c3 ]5 Q: Y$ S2 u  J$ y- |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

5 I: s' {! f4 ~8 m' n2 @, D
! l$ z- _- o  M6 u& c$ \用这个公式错了么?
还是说只是纯粹的计算出错?

chulinlong

3# Maths
6 g. Y8 G3 P* N$ x
+ Y. D" m  q7 j( s
- _- P( X) Y1 ~这个公式对的