🚀 go-pugleaf

I am a grad student and did my undergraduate thesis on air friction.  i
also am a model rocket enthusiast.  First, the best equation for air
friction seems to be f=kv^2 for objects of this type.  that k can be
almost anything, but can be calculated from other rockets and experiments
(try running the rocket through a tub of water).  the problem is that
most class projects use small rockets with big engines so they go real
high.  It turns out that some of these rockets may reach speeds of 95% of
the speed of sound and that equation only works for speeds of between
50-70% the speed of sound.  If you want better results, use a larger
rocket and underpower it.  I might suggest the Phoenix missle by Estes
(you can still find them if you look arond) and put enough tape around a
C size engine to make it fit the D size compartment.  It makes lots of
noise and smoke and goes about 200 feet in the air and is extremely
predictable.

On Tue, 10 Jan 1995, Robert J Erger wrote:

> I am writing to discuss the use of model rockets in the high school
> curriculum.  For the past five years we have used model rockets as a
> project.  Each year we try to do a little more with our rockets.  My
> students use an altitude finder to determine the height that the rocket
> achieves.  We compare this with a height that we calculate based on
> information that we receive on the rocket engine.  I noticed that their
> calculations were way off, and I was wondering if anyone does this and can
> provide me with s ome equations for correcting for air resistance.  I know
> that if would be hard to account for aerodynamics, but somebody out there
> may have some suggestions.=20
>
> I don=D5t want to make it very complicated; because, some of my students ar=
> e
> lacking in math skills.=20
>
> We use the thrust and impluse information that is provided off a chart in
> the engine packages.  We find the time that the force is provided by
> dividing the impulse by the force.  We may be doing the project correctly
> but I don=D5t have anything the compare with and I would appreciate your
> input.=20
>
>
> Robert J. Erger II               I         SSSSSSSS    X       X
> Sherman High School              I         S=09        X     X
> Physics Department              0I0        S             X   X
> 2201 E. Lamar                  0 I 0       S=09          X X
> Sheramn Tx 75090              0  I  0      SSSSSSSS        X
> jerger@tenet.edu              0  I  0             S       X X
>       =09=09=09       0 I 0              S      X   X
> =09=09=09=090I0               S     X     X
> =09=09=09         I         SSSSSSSS    X       X
> =09=09=09=09 I=20
>