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.]

" S% k* _0 A% {4 g2 O
so far what I have done is used the equation for GPE
which is
U = - (G me m) / r

1 n+ t- m  M$ Q1 y: vwhere G is 6.674e-11 Nmkg-2
. R) P3 S; Z! A5 O- \6 ume is the mass of the planet 5.1e24 kg
m is the mass of the space ship 5.9e4 kg
0 J7 u/ S+ Z& ~* D! g7 \; yr 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

4 u" g. J- K2 \: }" O
用这个公式错了么?
还是说只是纯粹的计算出错?

chulinlong

3# Maths
0 a, m. X* s2 @$ k# p7 N

+ c+ D9 {: N/ S+ U7 w这个公式对的