空氣的浮力Buoyancy of air

[tomu921]

這個很沒趣味.....

但恭喜你發明了胃片減肥法

[idsun]

甚魔是 "care" 掣??

[roidroid]

Ah i finally see.

The inflating balloon allows the volume of the container to increase, but it still weights the same - therefore it's overall density has reduced.

(same weight, but now a bigger size)

Thus - as a whole it has become less dense.

very interesting experiment