① a=(r/(h + r))^2*g
② a=w^2*(h + r)
③ n=w*(t*60*60)/(2*Pi)
④ t=47
⑤ h=340000
⑥ r=6300000
⑦ g=9.8
解得:n=31.04
另:地球半径为R=6.37*10^6m
mω²(h+r)=GMm/(h+r)²
==>ω²=GMm/(h+r)³
ω=2π/T
==>T² =4π²(h+r)³/GM
GM/r² =g
===>T² =4π²(h+r)³/r²g
T =[2π(h+r)/r ]×√[(h+r)/g]
=2*3.14×1.05×830
≈5400s =1.5h
47h/T ≈31.3圈
先用GMm/R^2=mR(2π/T)^2将运行的周期求出来,注意R=H+R地。
再求圈数N,N=47h/T。