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]
: C  C/ T9 w: @' e( F: E
  j8 M% ~5 V: E) S0 T[Specify units of 'J', 'kJ', 'MJ' or 'GJ' in your answer.]
5 {0 v5 }$ d& g- s

. y# t+ x& y  K. Y4 E" ]so far what I have done is used the equation for GPE
9 q9 P0 g! c) H1 ]; O4 Qwhich is
8 ]" X$ _5 a$ J/ y' W6 AU = - (G me m) / r
3 r8 \3 W$ d& o* u
where G is 6.674e-11 Nmkg-2
8 W" w) |% c; j+ j( @0 ~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

  o, Y+ N, m! V用这个公式错了么?
; z5 ~' j' g4 |% K9 v3 m) m8 D2 g: P还是说只是纯粹的计算出错?

chulinlong

3# Maths

0 I; a3 P$ W8 t) O
这个公式对的