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]

( j8 P$ f5 i+ \+ W/ E[Specify units of 'J', 'kJ', 'MJ' or 'GJ' in your answer.]


- N. N0 A0 m. P7 w: cso far what I have done is used the equation for GPE
& D$ O2 O  s& Wwhich is
  j& l3 r0 D) _% l/ A4 `! w! zU = - (G me m) / r

; X" o7 w2 A- K2 g+ Ywhere 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
" f; ^3 L3 k5 M/ \- Ar 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

5 k  ?5 T8 u; p' F
9 g" k0 x* q0 O" l. o* V; A$ N用这个公式错了么?
8 H5 W% S5 Q% Y& l5 X还是说只是纯粹的计算出错?

chulinlong

3# Maths

+ @4 K0 N8 x# s( }( A# T& K/ P
这个公式对的