Posts Tagged “science experiments”

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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               “Teaching means creating situations where structure can be discovered.” –Jean Piaget

Many science teachers struggle with the idea of free exploration. Free exploration takes advantage of the natural tendency for children to just mess around with materials, without following any rigid procedures. If you have ever watched a child playing in sand, you have seen free exploration.

I have observed some preservice teachers struggle with a hands-on science lesson because they pass out the materials to the children and then they try to explain what they should do with them. More experienced teachers know that once children start to interact with the materials, they begin to tune the teacher out. A better strategy, therefore, is to explain to the children all that they need to know before passing out the materials.

Free exploration purposely allows students to mess around with the materials. It is a shame that for so many teachers, science experiences are always canned (first do this, and then do this). I have no objections to well articulated experiences that lead to discovery, but students also need opportunities to mess about. Each time they change something and see the result, they are developing ideas and approaches that will deepen their abilities to design and understand experiments.

The virtual world can be a great place to mess around without causing a great mess! The activity object, “Space Objects Interaction Explorer,” presents a great canvas to mess around with. Students are presented with two celestial objects, larger than the other. By changing the size and direction of the arrow, they control their initial velocities. Then they hit the play button and the objects move according to their initial velocities, and their motion is immediately influenced by gravity. Lines are drawn as the planets move so the orbital paths are evident.

Experienced teachers also are aware that challenges can really keep students engaged, such as with GEM’s Bubble-ology, where the teacher walks around and says, “Okay, let’s see who can produce the largest bubble!” or “Wow, great! Now, can you blow a bubble within a bubble?”

In Space Objects Interaction Explorer,” the first challenge is easy. Make the objects collide. A fiery explosion rewards success, but there is no big bang—of course, contrary to Hollywood misconceptions, sound does not travel in the vacuum of outer space.

The second challenge is to make the smaller object orbit the bigger one. Most children can’t do this at first, but neither can most adults. It is interesting that most adults know what an orbit is, but they can’t at first produce one. It is very different being able to define the term orbit versus being able to explain why an object orbits another. Through trial-and-error learning, both children and adults can get one object to orbit the other—and develop intuitive ideas about orbits.

Inevitably, the first orbit produced by the learner is not a circle but an elliptical orbit. The third challenge is to achieve a circular orbit. When this task is completed it helps students really understand that orbits are an interplay between velocity (moving tangentially to the orbit) and gravitational interaction. Then, when orbits are explained, students have the experiences to understand why they occur.

 The fourth challenge involves three objects and asks that two of the objects orbit the largest one, which I will call the star. In putting this together, students (and adults) usually place one object closer and one farther from the star. And they initially make the farthest one have the bigger initial velocity. When they hit play, the nearest object crashes into the star and the larger object shoots out of the star system. Through trial-and-error learning, students will get it right, and later when they learn that Mercury is the fastest moving planet, it isn’t just an isolated fact to be memorized, but becomes an example of a concept they already know.

The last challenge is, appropriately enough, the most difficult to achieve. Appropriate because the really smart kids that solved the other challenges with great speed are fully engaged as everyone else catches up. The challenge is to make the small object orbit the medium object as the medium object orbits the largest object, or in other words, they are challenged to create a moon that orbits a planet, while the planet orbits the star. Students can, of course, adjust the position and velocity of the objects, as well as their masses. Success with this challenge isn’t easy and it takes a lot of messing about, but it is fun to see the interactions and patterns drawn of the paths followed. And when success arrives, it feels sweet!

References:

Adaptive Curriculum. (accessed August 7, 2008). Space Objects Interaction Explorer. https://www.adaptivecurriculum.com/us/details/USSSM150202

Barber, J. (1987) Bubble-ology (Great Explorations in Math and Science). Berkeley: Lawrence Hall of Science, University of California. http://www.lawrencehallofscience.org/gems/

Hawkins, D. (1965). Messing about in science. Science and Children, 2(5), 5-9.

Piaget, J., & Inhelder, B. (1967). The Child’s Conception of Space. New York: W. W. Norton.

 

 

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