It only looks like smoke.. It's 20F outside and PV=nRT...

The 6' air line leads to the Serfas FP 200 bike pump, stage right.
The envelopes by the rocket base contain "burst membranes".
The Omega DPG5500B-500G digital min/max/zero pressure gauge records
the burst pressure.

We recorded video w a 5dmkii. Pinnacle Studio 14 (NLE) let us grab
this frame when the rocket blasted off. We use the video's audio
track to determine the time of flight, which can be used to determine
the rocket's initial velocity and ultimate height.

The initial velocity is determined by "burst chamber" pressure, volume,
trigger ("burst membrane"), and the Venturi effect that results when the
compressed air bursts the membrane and enters the smaller radius launch
tube: the launch tube pressure is lower than the burst chamber pressure,
but the launch tube air velocity increases proportionally. Depending on
how well the rocket "fits" the launch tube, "blowby" and friction (as the
rocket works its way up the "launch tube") can have a material adverse
effect.

The launch Pressure*Volume product approximates the kinetic energy Ek
(the work needed to accelerate a body of a given mass from rest to its
current velocity) is given by Ek = 0.5*mass*velocity^2


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