Glenda Ellis (Williams School)
marked a 30 meter course around the perimeter of the room, gave us stop
watches, and we measured the time it took for each of us to walk the course.
From this, the walking speeds for each of us were calculated and compared.
Speeds ranged from 1.20 to 1.67 meters/second. Ken Schug recalculated the speeds
in miles/hour! And we then had an interesting discussion about how our speeds compare
with walking and running speeds of various animals:
Erma Lee (Williams School)
turned us into bean counters! She gave us dried, red beans and asked us to
estimate how many beans it takes to go around a person's
shoe. Then we had to measure it! Erma asked us to trace an
outline of our shoe on an 8.5 in x 11 in paper, and then
we did the measurement on the tracings, laying the beans
end-to-end. The distance around was measured in "bean
lengths." She asked us to measure the surface area within
the tracing, a sort of surface area of a shoe. To do this
we placed as many beans as possible within the outline and
in a single layer, and counted them. We repeated these
measurements for our hands using the same techniques. We
found that the surface area of our hands was about 75%
that for feet, and the perimeter of a hand (fingers closed)
was about 80% that for feet. What a rich learning
experience! - involving measurement, observation,
comparison and conclusions. Thanks, Erma!
Karlene Joseph (Lane Tech HS)
had us write hidden messages on 8.5 in x 11 in paper by using
phenolphthalein as an invisible ink. When we sprayed the
paper with an ammonia solution (a base), the
phenolphthalein turned red, and our messages appeared.
Spraying with vinegar (acetic acid) caused the red to turn
clear so the messages would disappear!
Now that she had us "hooked," Karlene did a titration of 15 ml of vinegar with ammonia using phenolphthalein as an indicator, and we found that about 12 ml of ammonia was needed to turn the vinegar to deep pink. Thus, the molarity of the ammonia was 15/12 = 1.25 times that of the vinegar. A wonderful phenomenological approach, Karlene!
Great ideas! Don't miss the next one!
SEE YOU THERE!