Physics in the Mathematics Curriculum Summary

Friday, July 5, 2002

Magnets and Compasses
Possible source of inverse cube relationship.

Discussed need for students to be more familiar with handling measurements and computations with significant digits.

Discussed reporting out of each work grouping. What is the objective of our efforts here? Development of a polished presentation for the other groups here or the development of web based resources available to many.
Recommendation: each group take 10-15 minutes summarizing their work, then referring others to web for details. We still want to see what the other groups are doing, but that it should not take 3-4 days to complete this reporting out. We think we can get the jest of each groups work through a 15 minute presentation just as well as an hour presentation.

Discussed morning activities. How are things going? Number theory is very helpful in extending our knowledge of content. Enjoy the teaching style of Bowen as a model of good teaching of mathematics. Like the flexible direction in number theory presentation, we can go with where the class is going. 11:00-12:00 teacher reflection. If the theme is for us to be reflective teachers, we may not be achieving this in the structure and activities we have done so far. We think the idea of reflection on our teaching is very valuable, but we may not be getting there yet. It doesn't seem like we are finishing activities we start (videos seen, article read) Maybe we are trying to do too much with too little time. Perhaps we should model teacher reflection in these activities more.

Where are we going from here? We think we will be able to put together at least 5-6 activities by the end of our three weeks here. We have 4 in process (pinto beans, blow gun, tubes, and bouncing ball). We will "play" for a day or two more, then look at polishing these activities during the second and third week.

Tube Tones
Tested out 4 inch diameter corrugated sewer tube for tone. Although it is a little difficult to swing, you can clearly hear three distinct tones as the speed of the tube is increased.

Watt meter
Plug in some electric appliance to the watt meter (measures kilowatt-hours of electricity consumed). Record kilowatt-hours at regular time intervals for five minutes. Plot the kilowatt-hours consumed as a function of time. The area under this curve gives the power consumed during this time period. Try with a hand mixer and put variable loads on the mixture.

Magnet on the Meter Stick
Place a compass at some point on the edge of the meter stick (the needle pointing north should be perpendicular to the length of the meter stick. The compass needs to be placed as far as possible from any metal objects to avoid interference, so you may want to place the compass on a two-by-four, and measure distances on the two-by-four. Position a magnet at distance x from the compass. The magnet produces a field which affects the needle of the compass. The relationship of x with the magnetic field is an inverse cube.

Measure the angle of deflection two times with the magnet in a specific position (turn the magnet around, reversing poles).

Data Recorded:

A regression analysis shows

Matches this data quite well.

Here's why this is an inverse cube relationship:

Let r represent the distance between the center of the magnet and the compass. Let d represent the distance between the center of the magnet to the edge of the magnet.

Temperature recorded using Two CBLs - Celsius versus Fahrenheit Scales

Collect temperature of cooling liquid using two probes, each attached to a CBL. Plot both sets of data simultaneously. Have students find the appropriate multiplier to stretch and vertical shift to convert one plot into the other plot.

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