Re: weight of a bird in a cage

[Ludwik Kowalski <KowalskiL@MAIL.MONTCLAIR.EDU>]

Jim wrote:

> ...The HS students used a video camera to read the scale and watch the
> fly - stop action. When the fly flies, the weight was always greater than
> when sitting.  My HS studnets reasoned the downward force would be
> always greater than the weight of the bug, cannot break even!. Hopping
> from the bottom increased the weight reading beyond the normal flying
> weight and hopping from the top gave a temporary decrease, etc.

Neat. This was not obvious to me from the first message. Next time ask
students to see if the distance (between the flying insect and the bottom)
has an effect of the scale reading. Can both the fly and the scale readings
be captured by your camera. Actual numbers would be useful here, and
probably worth publishing in TPT.

This thread was triggered by the debate about aerodynamics. Which claim
or counterclaim is supported by Jim's observation? Experiments are worth
performing and publishing when they help to clarify mental models.
Ludwik