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]
" ~$ N7 j; ^9 B' J, b0 j& q' C
[Specify units of 'J', 'kJ', 'MJ' or 'GJ' in your answer.]


. V  S, |5 d7 yso far what I have done is used the equation for GPE
: P$ T+ r# Q6 H5 G. xwhich is
" Q; A- E3 Q/ s5 t9 u$ W) x( iU = - (G me m) / r

where G is 6.674e-11 Nmkg-2
me is the mass of the planet 5.1e24 kg
% A! a$ W- N  P; q! I: M$ ^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

. V: L; T/ O. J( l$ b. K
用这个公式错了么?
8 R( L; Z5 y. ~; x0 V/ H/ j  D还是说只是纯粹的计算出错?

chulinlong

3# Maths
& A+ p  B+ l2 H* F

4 {+ Y! X3 w) I/ I( f, ~" E0 C这个公式对的