mamasing

I agree, I heard that astronaut cannot pee or shit while they are in space.5.39.217.76" P; Z+ p& [( G2 u
It must be a painful joruney.tvb now,tvbnow,bttvb& C% k7 r6 k; b) f
Oh BTW, if your lecturer talks about "地心引力" in your Physics class.5.39.217.76& [* A5 M9 P/ v4 A: V1 Q# A9 @
I suggest you pack and pick other subject instead, if you really like Physics,
6 o6 C* n2 p  z5 N6 vyou need to switch school.5.39.217.765 M6 F% O3 K( q5 `) h0 m* V( C
There is no 地心引力, but "gravitational" force only.
  T, Y# I: O. ]5 @9 U. V1 ]tvb now,tvbnow,bttvbA simple meaning of Gravitational force = the force of attraction between any 5 W! z9 O2 j- \9 a- C/ W
two masses.
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Gosh, I got fooled by my HK Physics teacher many years ago.