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Àü ÇÐ±Þ °ðµ¿ Å½±¸ ¹®Á¦ Whole Class Inquiry problems
º¸³½ ³¯Â¥ 2008/09/16 È¿äÀÏ ¿ÀÈÄ 12:26:17
º¸³½ »ç¶÷ "Huffhaus" <huffhaus@pacbell.net>
¹Þ´Â »ç¶÷ "Sean Sletten" <sslett1@isd77.k12.mn.us>,
Âü Á¶ generalscience@list.nsta.org
Sean,
You may like this: Finding the thickness of aluminum foil.
You need to purchase an aluminum bar at your hardware store. They come in one inch by onequarter inch by 6 feet.
Take it to the metal shop and cut it into different lengths from 2 inches to 12 inches.
Now, the width and thickness are probably good to 0.001 inch by the manufacturer. The students need to measure the length, which probably is not to that tolerance, to find the volume of the bar they get.
By multiplying 0.250 inches times 1.000 inches times the measured length, you get the volume in cubic inches.
But we need the volume in cubic centimeters, so multiply by 2.54 three times.
Now, the mass of the bars can be quickly measured in grams on your scales or balances.
Density = mass/volume and you can quickly assess the skills of your students by seeing how close they come to 2.7 g/cc.
This should take about 15 minutes.
Now, tear off pieces of aluminum foil and ask them to find out how thick they are.
If the class is good, students will figure out that since D = mass/(length)x(width)x(thickness), they know D, they can measure the mass on their balance, they know the width (12.000 inches) and can measure the length. The only thing they don't know is the thickness.
Different manufacturers roll their foil to different thicknesses, so now, it is up to the whole class to make careful measurements and to intercompare their results.
This is not only a good exercise in Whole Class Inquiries, but, perhaps, a good introduction to indirect measurement.
Brad Huff
Fresno, CA

Sean Sletten wrote:
Hello everyone. I have a question for all of you concerning WCI's (Whole Class Inquiries). I am looking at implementing WCI's into my units in Physical Science, and I am interested to see if anyone has any suggestions for my first one on Measurement. I am looking for a very thought provoking problem involving these concepts: 1) Measurement involving either length, mass, or volume; and 2) Converting between SI Units. I would like this problem to be a very thoughtprovoking question that should take all of about 30 minutes to solve as a class. Any ideas? Has anyone had any experience in using WCI's in their classes? If so, what suggestions do you have for someone who is trying it for the first time? Thanks for your time!
Sean
Sean Sletten
Science Teacher
Mankato West High School
