To calculate the volume of helium required for neutral buoyancy based on the mass of components and blimp.

**Assumptions** –

- Temperature is constant.
- The gas is purely helium
- The density of surrounding air is constant
- Atmospheric pressure is constant

**Derivations**

Using the equation -

*Buoyant Force = Density*

_{air}X Volume_{air displaced}X g

For the blimp to float -

*Buoyant Force = Weight of Blimp*

Therefore -

*Density*

_{Air}X Volume_{air displaced}X g = (Mass_{Blimp}+ Volume_{Blimp}X Density_{helium}) X gwhere,

Mass

Mass

_{Blimp}= Mass_{Components}+ Mass_{Mylar}

Since,

*Volume_*

_{air displaced}= Volume_{Blimp}

On simplification, we get -

**Volume = Mass**_{Blimp}/ (Density_{Air}- Density_{Helium})

where,

*Mass*

_{Blimp}= Mass_{Components}+ Mass_{Mylar}

I hope the equation can help the team members to determine the approximate dimensions of the blimp.

### Air Swimmers Blimp

For the past few weeks, I have been playing around with the air swimmers blimp to gather some intuition.