GMm/r^2=mr(2TT/T)^2
On the surface of the earth, GMM/r 2 = mg.
The solution is r=
(2) "Shenzhou VII" spacecraft makes uniform circular motion around the earth,
GMm/r^2=mr(2TT/T)^2
On the surface of the earth, GMM/r 2 = mg.
GMm/r^2=mv^2/r
Solve v=
3) Throw a small ball vertically upward at the speed Vo on the surface of the moon, and after time t, the ball falls back to the throwing point. GM month m/r 2 = mg month
0=Vo-g month t/2
Solve m month =