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]
& Q8 r/ v( E/ ?9 E
[Specify units of 'J', 'kJ', 'MJ' or 'GJ' in your answer.]

6 l/ U9 G/ O+ ]1 z
3 D3 g' l/ [! Q) v4 ]so far what I have done is used the equation for GPE
7 A/ B4 n4 F* V" B/ Zwhich is
2 I) c& p9 |: g. R; bU = - (G me m) / r

" X6 [0 j7 B& p/ Cwhere G is 6.674e-11 Nmkg-2
. ~' x/ B! W4 l1 c) q7 Yme 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

4 z3 W$ v5 E: o1 E$ e$ Q& M
用这个公式错了么?
' z# z% `- L# T9 t5 I还是说只是纯粹的计算出错?

chulinlong

3# Maths
) k  s2 s1 X. \. a" K7 r  v
$ b3 ^  B5 C4 w* ?: O' L2 [- ]2 V  k
: J( @1 {7 b' M2 [0 E这个公式对的