Math help

[shooter]

I have a "leftover" helium tank, basically 4' X 8"  (calculated Volume using 45")
the internet tells me Vol = .037067 M^3


what the ducks can't find;
the gas is at 2,000psi, I want it at atmosphere @ sea level
I have the density of He  .179Kg/M
Got air at 1.29Kg/M


my endgame is to know, on a napkin, what the "lift" of my unknown volume can move with initial acceleration  at 0

thanks
dave

[acheld]

Medical(for MRI machines, usually )?   Helium Trimix (eg welding gas, about 90 %)?  Grade 5 (diving, usually 5000ppm or less impurities )?   Balloon grade( about 80%)?


Going for a suborbital flight, are we?

If temp is constant, P1*V1=P2*V2:   2000psi * 37 liters = 14.9 psi * X liters

So you have about 5 m^3 of gas, or about 175 ft^3.

Lifting coefficient of helium is about 1.1kg/m^3, so you could lift about 12 pounds.   Seems like it should be more.

That's my napkin, sans the ketchup I just spilled.

[shooter]

thanks!!!


I was guessing <20lb 
thinking once friction  and static weight is overcome maybe more, but your napkin value is good by me!


I'll keep to the ground, let my sUAV do the flying.


n ya 5 9's gas but i'm not that picky