Consider a balloon of mass 0.030kg being inflated with a gas of density 0.54kg/m³.

What will be the volume of the balloon when it just begins to rise in air of 1.29kg/m³.
Take g=10m/s²

2 answers

the weight of the balloon is .030 * 10 = 0.3 N
the weight of the gas of volume v is 0.54*10 N
The lifting force of a volume of v m³ of displaced air is 1.29v N
so, we need
1.29*10*v = 0.3 + 0.54*10*v
or
1.29v = 0.03+0.54v
...
Jeriq