1. Think of one feature that could be changed and how its
alteration
will affect kite lift or drag. You might consider the concepts from the Web
Quest or even something that isn't well researched. Be sure it can be tested
easily with a fan and spring scale set up shown below, potentially
combined other
classroom materials. If you are having trouble thinking of ideas
or are ready
to predict what you will measure, you can play with this kite
modeling software
called KiteModeler:
http://www.grc.nasa.gov/WWW/K-12/airplane/kiteprog.html
2. Some things to know about testing:
Testing should
focus on the change in lift and / or drag as a result of changes in
the kite.
Balance and
center of gravity can also be observed during testing.
Testing may be
conducted with a miniaturized model of the kite or a duplicate of the
kite to be flown.
Testing should
be repeated at least three times in order to assure validity and
reliability of data.
Measurement of
forces will be conducted in identical ways on kite flying day.
3. Fan and spring scale set up:
The fan we will
use produces wind speeds up to about 10 miles per hour. Wind speed
can be measured with a
wind meter. The fan would be placed to the left of the image
below to produce wind.
The spring scale
measures force in Newtons, or kg*m/s2, in a range of 0.05
to 50 Newtons. For small or
medium-sized kites, a 250g/2.5N scale is best. Larger kites
may require 1000g/10N or 5000g/50N
scales, particularly when flying in natural wind.
A protractor set
parallel to the floor will be used to measure the angle of the
bridle.
A scale can be
used to measure weight (mass* gravitational force) of the kite in
grams, which must then be
converted to Newtons
using the gravitational constant (9.8 m/s2) and a
conversion factor (1000 g = 1 kg).
A hand-held wind
meter will measure wind speed in miles per hour.
Trigonometry
will be used to determine the lift and drag vectors, using the angle
of attack and force vector
along the bridle.
Start your rough draft of the test, below:
The ONE FEATURE you will test for is:
What is your hypothesis?
Briefly describe your experiment in the space below and on the
back of this sheet. Use sketches to help you explain.
