Is It Shocking?
To better understand electricity, students investigate the properties of materials based on their ability to dispel static electricity. They complete a lab worksheet, collect experimental data, and draw conclusions based on their observations and understanding of electricity. The activity provides hands-on learning experience to safely explore the concept of static electricity, learning what static electricity is and which materials best hold static charge. Students learn to identify materials that hold static charge as insulators and materials that dispel charge as conductors. The class applies the results from their material tests to real-world engineering by identifying the best of the given materials for moving current in a solar panel.
"What's going on with your hair?" Contact with the plastic slide has left this child's hair positively charged so that individual hairs repel one another. The hair may also be attracted to the negatively charged slide surface.Copyright Ctd 2005, Flicker http://www.flickr.com/photos/49196923@N00/48616367/
Electrical engineers must understand the electrical properties of materials in order to select appropriate materials to use in designing devices and projects. One everyday example is a typical electrical cord: the inside of the cord and the prongs are conductors in order to permit the flow of electricity while the outside is an insulator in order to protect people touching the cord from electric shock. In the activity, students act as engineers tasked to find materials that do not hold static charge and permit electricity to flow easily. Based on what they learned in the associated lesson, students understand that they are looking for a conductor; an analysis of their testing observations determines the best conductor out of the provided materials.
After this activity, students should be able to:
- Explain that static electricity is the buildup of a charge (either net positive or net negative) over a surface.
- Correlate the buildup of static electricity in a material to its properties (identify whether it is a conductor or insulator).
- Explain why it is important for engineers to choose the best material for electrical jobs.