Should We Build a Dam?


Brandon DeBritzby Brandon DeBritz

A Junior High STEM Exploration into Hydroelectric Energy with the use of the PowerWheel

When we talk about electricity and where it comes from in the Pacific Northwest, hydroelectric energy production is a key source and natural opportunity for teaching.  Part of the curriculum used in the South Kitsap School District in Port Orchard, WA is SEPUP ‘Weathering and Erosion’.  Students explore the Earth processes of weathering, erosion, and deposition all the while considering where to expand residential development in an expanding fictional town along the northwest coast.  This year, students at Cedar Heights Junior High were presented with a new factor to consider for this situation, ’should we build a dam on the town’s river to provide energy for the expanding electrical needs of the city?’ This new situation opened the door for a STEM unit, ‘The Energy of Moving Water’ from the National Energy Education Development (NEED) Project (free teacher and student curriculum guides are available from their website  www.need.org).  From this platform, students were engaged in activities and research to explore: what electricity is and how it is created, the designs of a hydroelectric dam and how they work, as well as many of the environmental, economic, social, and political issues around the construction and use of dams. Through a school partnership with RB Industries and the PowerWheel, students explored the fundamental elements of creating electricity through the transfer of moving water.  Picture #1     Read the rest of this entry »


The Laws of Physics


tamiby: Tami O’Connor

My husband and I just returned from his reunion at Cornell University.  He attended the law school, so, while he reminisced with his friends about this loophole and that exception, I became curious about other events being held at the university.  I scanned the various offerings, and though he was interested in the course entitled “Effective Strategies for Conducting Online Legal Research”, the class entitled “Favorite Physics Demonstrations” at 2:00 PM jumped off the page at me.  The immutable laws of physics were just the diversion I needed! I made my way to the Physics building, arriving early.  I found plenty of hands-on materials placed all around the lecture hall for the spectators to “play” with.  To my delight, I had a “reunion” of my own with many products from Educational InnovationsSinging Rod! Air ZookaTornado TubesSound Tubes!  A Hand-Cranked generator!  And more…  All my old friends were here! The presenter’s table was covered with classic physics demonstration items: a Van de Graaff generator, bicycle wheels, magnets, and a host of other items. He had sound devices, and a table covered with glasses filled to varying levels with water.  From the 30’ ceiling hung a cable with a ball weighing about 10 pounds.  Fog leaked from a container of liquid nitrogen, and a large wooden box stood nearby.  I just knew it would be a fun afternoon!

Laws of Physics

What do paint and perfume have in common?  Using Bernoulli’s principle, the presenter, Dr. Philip Krasicky demonstrated how, when air flows faster, its pressure decreases.  Using two wide-diameter McDonalds’ straws, he stuck one in a glass of water.  With the other, he blew across the open end of the first straw.  With the resulting low air pressure, water rose in the straw and sprayed, via the stream of air, onto the front row spectators.  He explained that devices like paint sprayers and perfume atomizers employ this principle to spray their products.  Clearly, these were some laws we could rely on!

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Hovercraft Addition – Collisions!


Jim DHS Oct '12by:  Jim Fiddes I recently used this extension of the balloon-CD hovercraft plans in Norm Barstow’s blog for a middle school physical science lab, but it could be easily adapted for a high school IPS class. It works as inquiry for higher-achieving students, but just as well with more detailed direction, for regular classes. HC1By the time you do this collision addition, your students should be attuned to the fact that “hover” means just that—there is no lateral motion without some sort of propelling force. The hovercraft will just sort of sit there and maybe spin a little. Students looking for more dynamic action will be disappointed. As a mid-point review between the two hovercraft labs, you may show the “Junkyard Wars” episode on hovercraft, in which it’s abundantly clear that hovercraft need two forces—one to levitate the craft, and another to propel it. Students provide the propelling force, accelerating one levitating hovercraft into another, and observing the results. Illustrationwww.xinventions.com Basically, this addition explores the ideas of Newton’s Three Laws, inertia, momentum (First Law), Newton’s Second Law (force equals mass times acceleration), and even Newton’s Third Law (action-reaction) using collisions between differently-weighted hovercraft. Weighting is done with the simple addition of pennies or washers onto the CD (see below). While it’s difficult to quantify acceleration here, mass can be calculated and compared. If you have a SmartBoard, you can do some cool on-screen demos as lab prep and summary, too! More about this later! Read the rest of this entry »