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 e, o* b" W9 \4 ?* l
& v) @3 {" Q2 n! p! q( G* i[Specify units of 'J', 'kJ', 'MJ' or 'GJ' in your answer.]
7 C$ r' {: ~9 k1 ^8 ^! e* B% E0 f
: d7 }. @0 w8 t; j
/ {! c0 Z, }9 O' i  dso far what I have done is used the equation for GPE
* V! Y+ K. |' D9 [" D- F" ^( jwhich is
U = - (G me m) / r
" ~+ k/ [1 g8 P
2 A. Z. D2 s3 i& x9 h2 zwhere G is 6.674e-11 Nmkg-2
me is the mass of the planet 5.1e24 kg
m 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

7 r2 f  K4 i/ s4 B
; Z7 {) J! H6 k3 R用这个公式错了么?
( C# O) V% x" o! s; a; A1 {  L7 _还是说只是纯粹的计算出错?

chulinlong

3# Maths
( E& x' g- Z3 }8 M" p3 f' n

: Y) t9 b0 ]* {$ b- {1 H; b这个公式对的