 鲜花( 0)  鸡蛋( 0)
|
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]% v( k. A; e- i6 W
' }* j5 S- y' E- i$ a
[Specify units of 'J', 'kJ', 'MJ' or 'GJ' in your answer.]
( [# V9 w( i1 `6 Q9 f4 W _, T
3 Y. ?! U$ Z' k4 y/ H
so far what I have done is used the equation for GPE- x p3 |0 @ `# w# ~# U8 c! a: o
which is
$ Q! b- \4 w. W+ ]% PU = - (G me m) / r4 L/ O3 w% q1 V, O( ^
4 @7 q2 F# t- o+ B R: t
where G is 6.674e-11 Nmkg-2
2 B# e$ l- E( |me is the mass of the planet 5.1e24 kg
4 d! `5 _; u5 F2 C; c3 {2 Om is the mass of the space ship 5.9e4 kg
, i! N; @0 V2 fr 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 |
|
狗仔卡
发表于 2009-11-10 21:41
提升卡
置顶卡
沉默卡
喧嚣卡
变色卡
显身卡
楼主
; O9 Q: H4 F Y, J