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]

# E$ i+ G9 q( }% b0 ^5 L4 j. N4 l8 ?& L8 D[Specify units of 'J', 'kJ', 'MJ' or 'GJ' in your answer.]
! ]8 ^- B! B: d; K4 Q
; @" C' Q* l* \; {" f
so far what I have done is used the equation for GPE
1 B0 t9 R- n) A, A) o7 M) d6 Awhich is
" A% B& C  X0 m6 t" q6 }+ H: I2 IU = - (G me m) / r
& b: q7 j% T# I0 C, p/ K
9 R8 g9 g: q, R% O. P: z8 pwhere G is 6.674e-11 Nmkg-2
me is the mass of the planet 5.1e24 kg
* z- Z# S6 Z8 x5 y/ wm 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

% j$ K: }! _3 R8 U( z0 m5 p- {/ |
用这个公式错了么?
& Z" \6 h$ W1 g- b( B9 N6 I还是说只是纯粹的计算出错?

chulinlong

3# Maths

; u9 M# ], n- y( @$ P) N
2 Z* o% ^3 i- J0 V这个公式对的