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]
( _1 b) A% z+ B. w& q
3 C6 m% t) Y( N* T7 c0 Y[Specify units of 'J', 'kJ', 'MJ' or 'GJ' in your answer.]

9 O" b% f# u$ F5 K/ C: o( H' Y
3 n0 w- q$ ~9 F* U* nso far what I have done is used the equation for GPE
which is
: @0 F( x: t1 V' t' V. E# QU = - (G me m) / r
" L$ s6 c( u: d! x' m1 M
where G is 6.674e-11 Nmkg-2
* l: x( g1 x5 Z  M: kme is the mass of the planet 5.1e24 kg
, A) W0 h; k$ j# Zm is the mass of the space ship 5.9e4 kg
7 h# _; J$ Q6 i$ D6 }$ Jr 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

% q2 u* ^/ f/ |* r
用这个公式错了么?
+ M9 D9 l! L! E  c还是说只是纯粹的计算出错?

chulinlong

3# Maths
; `+ `& _: n) Z0 ~& ?+ e
( G# g$ b% ]2 Q% k! u: l5 t* Q
) G) c+ [; }) R, k这个公式对的