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.]
: }( ~4 B% Q- _4 G' G
" C& `; t9 [& F
' v9 p: I+ D. `5 a+ mso far what I have done is used the equation for GPE
# {0 Q) }- m' l6 B+ @which is
) |( P5 s, _) }( E3 kU = - (G me m) / r

where G is 6.674e-11 Nmkg-2
me is the mass of the planet 5.1e24 kg
  o4 U( s5 ^0 w5 um 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

: ?3 M7 {9 {9 d, O6 d( S- m6 |
5 }& G' S) u6 C用这个公式错了么?
8 l8 b7 m8 t% n# Y7 ^$ B还是说只是纯粹的计算出错?

chulinlong

3# Maths

5 N/ l+ a8 K4 K/ U
这个公式对的