Solved
Spinout puzzle of Water, Air, Steel
Which is weighty a big balloon with 1m^3 volume of air or two basket balls?
Assume the weight of balloon gum (rubber) is 20g.
Conditions.
1.They are on your hand.
2. Throw and Catch ball them.
Static state ( On your hand)
Big balloon is 20 g. << Two basketballs, each is 600 g.
They are moving. When you catch them, the speed is v, mass*v affect your hands.
The mass of a large balloon is 
, Weight of balloon is 20 g.
Two basketballs. The mass is, 
,
, 
Therefore, we feel almost the same or more m-v attack in the big balloon than two basketballs.
t.t.