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Misconceptions | Engage | Explore | Explain | Elaborate | Evaluate
Misconceptions: Students and the teacher explore their understanding of concepts and compare them with accepted ideas. (top)
There are two misconceptions to explore, friction and Newton’s Laws
Friction: Webster’s defines friction as, “The resistance of a surface to the relative motion, as sliding or rolling of a body moving along a given surface.” Our Glencoe Science text book “Motion, Forces, and Energy” defines friction as, “rubbing force that acts against the motion between two touching surfaces and always slows an object down.” Wikipedia defined friction as, “the force that opposes the relative motion or tendency of such motion of two surfaces in contact.” Glencoe describes three types of friction: static, sliding, and rolling. Glencoe states that static friction is caused by attraction between the atoms of the two surfaces. However, Glencoe states that sliding friction is due to, “the microscopic roughness of the two surfaces.” However some scientists believe this to be an untrue statement. Friction is poorly defined and not completely understood.
Newton’s Third Law of Motion: This is not so much of a misconception as it is a nitpick, but kids like the controversy and loose definitions can lead to misunderstandings. Newton wrote in “Naturalis Principia Mathematica” that, “All forces occur in pairs, and these two forces are equal in magnitude and opposite in direction.” However most of us remember, “For every action there is an equal an opposite reaction.” The word “action” is not found in Newton’s definition of the law and isn’t “opposite reaction” redundant?
For more information about science misconceptions visit, http://www.amasci.com/miscon/miscon.html, or Google “science misconceptions
Engage: Capture the students’ attention, stimulate their thinking and help them access prior knowledge. (top)
The best way to do this is through a demonstration of how a Newton Car works. One hook is the how the Newton Car is triggered. You will note in the videos that students are using fire to cut the string. We have tried cutting the string with scissors, but they get in the way. I use cotton twine and soak the string with two drops of WD-40. However, the main hook is the spirit of competition aroused and further encouraged by awarding a pizza party for the students with the most creative Newton Car and the students whose car travels the furthest. “If you feed them, they will work.”
Explore: Involve students in an analysis of their explorations. Reflective activities clarify and modify their understanding. (top)
The research sheets allow students to hone their understanding of Newton’s Laws and motion concepts. They use the web to research misconceptions and hazy definitions of scientific concepts.
Explain: Involve students in an analysis of their explorations. Reflective activities clarify and modify their understanding. (top)
After completing the research the students work in groups to compare notes and revise their work. A class discussion and debriefing allows for further exploration.
Elaborate: Give students the opportunity to expand and solidify their understanding of concepts and/or apply it to a real-world situation. (top)
This occurs with the research, design, and modification of their Newton Car. I honed my problem solving skills by bending nails and skinning my knuckles on numerous harebrained projects in my dad’s barn. My father would give advice only when we asked or if we were about to lose a limb. He allowed us to succeed by allowing us to fail. The students are not graded on how far the Newton Car travels or how fast, they are evaluated on how well they improved their car.
Evaluate: Brainstorm with the students the standards and criteria for the assessments and evaluate throughout the lesson. (top)
Research sheets: Students work independently to research and synthesize information about Newton’s Laws of Motion, friction, force, and energy to assist them in the design of the car. Students compare their textbook definitions with websites about common misconceptions in science to determine if they are in agreement or not.
Socratic Dialog: Throughout the research and design process the instructor monitors student understanding as they complete the research sheets. Groups of students work together to compare notes and discuss their answers to the critical thinking questions. The instructor monitors the group discussions and facilitates a class discussion in order to attempt a consensus. The instructor also notes student understanding through conversations with students during the trial and test phase of the project.
Data Sheet/Journal: Students record data and modifications to their Newton car during the testing and trial phase of the project. Through critical thinking questions, the students demonstrate how an understanding of the concepts helped them design their Newton Cars.
Newton Car: Students construct a Newton car that demonstrates they have attempted to improve performance by reducing opposing forces and maximizing energy transfer. (top)
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