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I'm still working on my balloning project and now I have arrived at the problem of getting a accurate idea of a descent velocity/time. I am sure that the formula to get the velocity is:

[tex]\sqrt{m*g/0.5*\rho*A}[/tex]

Now density changes with altitude, causing a higher velocity at high altitude and a decreasing velocity while closing in on Earth. In the formula,mis the cross-sectional area of the parachute.is the mass of the payload andA

Question: How can I implement [tex]\rho(h)[/tex], that is the density as a function of altitude, into the formula above? Integration over [tex]\rho[/tex]?

My previous approach was to get myself the atmospheric densities for 4000 m-levels out of the 1976 U.S. Standard Atmosphere, to calculate the velocity by putting in each of the densities in turn, and finally to average the velocities. I don't know if this is also OK, but I can imagine that it is less accurate than a analytical solution I am looking for here.

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# Calculating a Parachute Descent

Can you offer guidance or do you also need help?

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