An air tunnel for kids

[LUDWIK KOWALSKI <KOWALSKIL@alpha.montclair.edu>]

> 10 Dec 1997 18:22:41 -0600 (CST)
> Date: Wed, 10 Dec 1997 18:22:26 -0600
> From: brian whatcott <inet@intellisys.net>
>
> Above all, I would like to see a high-school teacher tape up a cardboard
> 'wind-channel' with a domestic fan to drive it, a variac (or light-dimmer
> switch) to modulate the airspeed, a ball suspended by a knife blade in the 
> flow - and a force gauge like a spring balance or some such to measure 
> the air resistance over a 3 or 4:1 speed range....

A good way of measuring air resistance statically, rather than dynamically,
at least in principle. What would you suggest for measuring speeds of air
around the ball with accuracies better than 10% or so?
                                                          Ludwik Kowalski