Sunday, 29 May 2011

The Heat Is On

The materials I decided to investigate in this inquiry included aluminum foil, paper towel and newspaper. The mugs were large and only half filled with the hot water. A large portion of the heat was expected to be transferred from the water to the mug. Based on my knowledge of the specific heat of substances; I predicted that the aluminum foil would keep the substance warmer while the paper towel would not keep the water in the mug warm because of its porous surface.

The greatest challenge I experience was locating another thermometer. The course thermometer was damaged during shipping and as a result I had to rely on a kitchen thermometer normally used for testing internal meat temperatures. Due to the design of the thermometer, its accuracy was limited but it did reveal that the mug insulated with the aluminum foil had remained the warmest (130oF). The second warmest was the mug insulated with the paper towel (120oF) while the third warmest was the mug insulated with the newspaper (110oF). The control mug which did not have a lid cooled to 90oF. The exterior of the mugs all felt similar in temperature while the lids themselves varied in temperature. The results were due to the specific heat of the selected substances and the porcelain mugs.

The results obtained helped explained why the travel mugs which are designed to keep liquids warm are often constructed of stainless steel.  The stainless steel takes a large amount of time to absorb heat which in turn is released back into the liquid which keeps it warm longer. I believe that the paper towel may have kept the liquid warmer than the newspaper because of the insulating capacity of air. The paper towel surface was porous which trapped air. As this air warmed it created an insulating barrier which helped trap the heat inside the mug. The newspaper cover became saturated with water vapour (phase change) which would have contributed to heat lost.

I think students would enjoy this experiment if I could relate it to items they consume like hot dogs or pizza. Pizza has a tendency to remain hot longer because the heat of the sauce is trapped by the cheese layer (insulator). By testing three pizzas (one with sprinkled cheese, one without cheese and one with thick layer of cheese slices, we could investigate the insulating properties of cheese. The pizzas could be removed from the oven and the sauce temperatures regularly measured to see which ones cools the fastest (worst insulator) or slowest (best insulator).

I bet everyone of my grade 8 students would be engaged (and hungry) during the lesson.

Sunday, 15 May 2011

Engaging in Guided Inquiry

The focus of my guided inquiry lesson was determining the affect of different surfaces on the momentum of marbles. The question immediately took me back to my experience playing with marbles as a child. The strategies, skills and techniques developed over the years to adapt to various playing surfaces and conditions were seen as nothing but a game to my friends and me. Although our glass marbles varied slightly in colour, the slopes, the various playing surfaces (gravel, sand, dirt and clay) and the forces we applied to each marble all contributed to our ability to play the game well. It is with marvel that I reflect on the scientific aptitudes my friends and I had developed while engaged in this simple schoolyard game. The learning potential which existed as a result of our hobby would have been easy to integrate into a science lesson about motion. 

The initial step through which I gained insight into momentum involved an analysis of the materials available for my scientific inquiry. I began by selected an empty paper towel role to use as a ramp and a large textbook in order to assemble an inclined plane. This apparatus allowed all my trials to follow a consistent launch pattern as I released the marbles. The surfaces I decided to investigate included carpet, tile, concrete and wood. My three children always love to help and therefore were very involved in this portion of the investigation. We noted differences such as texture, dirt, grooves and finish in the surfaces selected. Three different marbles (large, small and plastic) were used in the investigation. Each marble was released from the top of the inclined and allowed to roll along the selected surface. For experimental purposes, each procedure was repeated three times and the data was recorded in a table. The average distances the marbles travelled across the surfaces were calculated.  The data collected clearly illustrated correlation between the mass of marble as well as the relationship between distance traveled along the surface and the texture of this surface. 
Engaging in a guided inquiry such as this allowed me to draw on previous experiences as I formulated new questions and hypothesis. It also allowed me to adjust my approach so I could better grasp the role that the mass of the marble had with respect to the velocity it had as it left the ramp. My initial approach had been limited to using only one marble but based on the observation of velocity differences, I re-evaluate my approach and the significance of the data.

The challenges encountered were primarily driven by surfaces that were not levelled or that had patterns that were irregular. The concrete flooring was sloped, the carpet had varying lengths of fibres while the wood floor had inconsistent groove patterns which all contributed to added friction. The tile flooring also had deep grooves that significantly impacted the momentum of the marbles. These factors were not within my control and played a large role in the path the marbles followed as they moved along the surfaces.
This type of experiment would benefit my students because it was engaging and related to their understanding of irregular surface, marbles and inclined planes. Students love to learn by doing (Buxton & Provenzo, 2011). The guided inquiry approach to learning allows students to develop a deep understanding of scientific concepts. This experience would provide the students with the necessary scaffolding for learning more complex and elaborate concepts as they progress through life. Teachers all know that not every student has the aptitudes necessary to follow a career path in science and technology but we do recognize the importance of learning these basic concepts which they can apply to all aspect of life. The concepts addressed in today’s classrooms provide the necessary framework so these students can become critical thinkers and scientific contributors in society.

The main challenge faced when a guided inquiry approach is taken in a classroom is the limited level of experience students have had with this style of self directed learning. Students in my school for the most part have been involved in scientific learning where teachers have taken a lecture and note taking approach. In order for inquiry to be successful, students need to be provided with some basic scientific vocabulary along with the tools necessary to explore their thoughts and ideas. Early in the school year, I am often faced with students that struggle and almost resist this freedom since they aim to please, look only for a single answer and never connect the learning to their previous knowledge. They need to be guided and supported in the inquiry process so they can begin to ask questions and seek the answers to those questions. As the year wraps up, many of my students have now developed a level of comfort and an ease in engaging in scientific dialogue which will have a lasting impression of the role of science in their life. 

Engaging students in inquiry based learning is a necessary component of science education. Students which are engaged learn more and can recall more. They benefit from instructional time that is meaningful and focused on scientific concepts which apply to their life. What better way to reach all types of learners than by making science meaningful and relative to their life. The lesson developed during this activity can serve as a stepping stone to motion, momentum, friction, forces and so on (Tillery, Enger & Ross, 2008). The understanding about the scientific concept can be used and applied to understand a number of other more complex and elaborate scientific concepts. Knowledge will easily be recalled because the students found the answers to their own questions.


References
Buxton, C. A., & Provenzo, E. F., Jr. (2011). Teaching science in elementary & middle school: A cognitive and cultural approach. Thousand Oaks, CA: Sage Publications.
Lantz, H. B. (2009). What should be the function of a K–12 STEM education? SEEN Magazine, 11(3). Retrieved from http://www.seenmagazine.us/Sections/ArticleDetail/tabid /79/ArticleID/208/smid/403/reftab/292/Default.aspx on May 14, 2011.
Tillery, B. W., Enger, E. D., & Ross, F. C. (2008). Integrated science (4th ed.). New York: McGraw-Hill.

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