Posts Tagged “JAVA”

 I was teaching a middle school lesson on static electricity on Halloween so I dressed up as “StaticElectricity.” We did the usual activities with balloons, such as picking up paper, rice crispies, and coffee grounds. I used water balloons, but of course, we filled them with air. I liked their shape better, but some students had difficulty blowing them up. One variation that one of my university students found was to draw two circles on opposite sides of a balloon. After that, one side was rubbed on hair, and the other was not. Students could accurately predict that the circle rubbed would pick up stuff, but most did not accurately predict about the other circle. It didn’t pick up anything, as the balloon was an insulator and the charges stayed where they were placed.

I found a good applet on static electricity. It is from PhET, the makers of The Circuit Construction Kit, which I positively reviewed in a previous blog. It is fine for a teacher to demonstrate that electrons move but positive charges do not, however, as a student activity it has limited potential. When you start, the balloon has no net charge. When you rub it on the wool sweater the balloon picks up electrons (shown in blue) and the sweater loses electrons. Now the balloon will stick to the sweater because positive and negative charges attract. if you move the balloon towards the wall it repels the electrons in the wall and it sticks to the wall. 

Other Resources for Static Electricity

Adaptive Curriculum’s Activity Object “Electric Force“ 

Kurtus, Ron. (2008). “Basics of Static Electricity.”

NASA, “Cling On

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The Circuit Construction Kit (CCK) is a great electricity resource for middle grade and high school students to conduct science investigations and learn about electricity. This FREE resource allows students to produce simple circuits using cells, light bulbs, resistors, and switches. Students can complete series and parallel circuits and they can observe the varying brightness of the light bulbs. CCK also allows students to move into the quantitative realm. Clicking on some additional buttons enables voltmeters and ammeters, and thus measurements of voltage and current can enhance investigations.

Well equipped elementary and middle schools will have batteries, light bulbs, switches, and wires to give students real experiences in constructing circuits. CCK can compliment the physical activities with virtual activities to enhance understanding. Unfortunatley, many schools will not have these physical resources so CCK is a way to help students explore electricity. And, I have not yet come across elementary or middle schools that have class sets of ammeters or voltmeters, so this is a welcome component.

Putting CCK to use

With my middle grade students we are using CCK to discover how to make series and parallel circuits, how to use ammeters and voltmeters, how current and voltage vary in different types of circuits, what are short circuits, and to observe that the ratio voltage/current is equal to resistance (Ohm’s Law).

Of course, the possibilities of how to use CCK are vast. Teacher goals, creativity, and experience level will make this a great resource in some classrooms. Most high school physics teachers will be able to instantly employ this tool. I wish that there were more structured lesson plans for using this tool at the elementary and middle school level so that teachers who are not yet comfortable with electricity could help their students have meaningful experiences. Some lessons can be found at the teaching idea page but these are almost all high school and university lessons.

The diagram above is one of the circuits I asked my middle grade students to construct. Then using a non-contact ammeter, they measured the current through all the branches of the circuit. They later used the voltmeter to measure the voltage across each of the branches.

Reflections in teaching

Working with middle school students, I found that they had few problems in using CCK. We started off constructing real circuits and then reproducing them in CCK where they used the ammeter to measure current at different places in the circuit. Although I know the importance of “free exploration” and wrote about it before in this blog, my regret is that I didn’t allow for free exploration with this virtual tool. Students really wanted to explore lots of things on their own, without me specifying what circuits to create. So, I should have allowed time for this before directing their explorations.

The Circuit Construction Kit is a simple but powerful tool that has a lot of utility in the upper elementary, middle school, and high school classrooms. It is a rich environment for free exploration and it presents many possibilities for guided-inquiry investigations.

 

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