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]
9 S7 J+ w8 c" @" F. @% F4 A9 _  n
- j: X/ }3 ~; [- i! D[Specify units of 'J', 'kJ', 'MJ' or 'GJ' in your answer.]
7 ^. h* g3 z/ C; P! ^$ U4 i9 o# v2 O

so far what I have done is used the equation for GPE
4 r2 G4 A3 B9 H4 \which is
U = - (G me m) / r

where 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

用这个公式错了么?
( S- d" _0 l+ T# ]8 a% `& U6 `3 s还是说只是纯粹的计算出错?

chulinlong

3# Maths

" v  `2 n2 g- I* a, J  p6 d& ]
9 Z( k, P  B( x: l; |2 a/ i$ C' Y这个公式对的