Activity 2.2


From: lindgren@tiac.net (Charles F. Lindgren)
Subject: Activity 2.2
Date: Fri, 13 Dec 1996 15:54:48 -0500 (EST)


I apologize for this being so long, but it's a story that must be told.  I
am in the middle of Activity 2.2 (pages 34-35) of the Teacher's Guide and
want to give you a progress report. I have had two of the greatest days
with this lesson!!! This is the end of my igneous unit. So far we looked at
igneous minerals and then at the rocks they formed. Then we looked at the
two major types of volcanoes (shield and explosive) and discussed the
reasons why they occur. As a part of this we watched last year's Nova
"Hawaii, Born of Fire" (excellent flick!!!) which led us to becoming
"Planetary Geologists."


Yesterday we created the cinder cones using different varieties of sand. I
used a VERY coarse sand (Sanabel Island Shell/sand), small mineral chips,
coarse aquarium sand, VERY fine Carribean white, and Hawaiian Black with
the curse removed. In addition to measuring the angle of the slope I also
had the kids measure the height and find the circumference by drawing a
line around the outside of the cinder cone. Then they poured the sand back
into the beaker and either measured the diameter with a ruler or simply
counted the lines on the graph paper. I had them pour the sand on to graph
paper that had each centimeter accented with .2 divisions in between. In
addition to doing this we digitally photographed "the best" cone of each
type from the top and side with a Connectrix(?) 8 bit black and white
camera and saved to disk. The kids loved it!!

Today we discussed the angles and why so many people came up with so many
different slopes. We had a great discussion of error! Then I asked them
what they thought the steepest slope they could comfortably walk up would
be (remember this?). They all fell into the same trap we did saying 35 to
70 degrees (I teach 8th grade). Then I broke out the 2 X 10 plank and
ladder and we tested our ability to measure angles. With one person doing
the walking, two spotting and one holding the ladder, everything went
smoothly. (Many people looked askance at me for trying this. I told the
principal and warned the nurse in advance.)

Now for the neat part! After it was over, I photographed the ladder/plank
at its maximum slope and put the pict file into the NIH program, and we
measured the angle using the software. It was incredible! The maximum angle
was only 32 degrees! They thought for sure it was going to be 65 or 70! We
then went back and did the same thing with the photos taken the day before
of the various slopes, heights, and circumferences. In one class ALL of the
slopes came out within 2 degrees of one another! Because they had done the
activity on graph paper, we had a ready scale to calibrate the software to
measure the circumference and height. They were impressed!

This lesson was one of the best examples of integrating technology into a
science lesson that I have ever seen. Thank you Passport to Knowledge for
giving me the initial idea.