Heat, Temperature, and Heat Transfer

When teaching the movement of heat, conduction, convention, and radiation should be addressed. Conduction is one way in which heat is transferred from place to place. Conduction means the transfer of heat by one thing touching another (Tillery, Enger, & Ross, 2008). Heat energy flows more easily through certain types of materials. For instance, heat energy flows better through a metal spoon than through a wooden spoon. Convention is the movement of liquids or gases from a warmer spot to a cooler spot (Tillery, Enger, & Ross, 2008). A convection current is a pattern of flowing heat energy. A radiator is a good example, which transfers the heat to the air by pushing boiling water that through a system of pipes. Lastly, another way heat energy is transferred from one place to another is through radiation. Radiation is the emission of heat energy in straight lines from a heat source to the surrounding areas (Tillery, Enger, & Ross, 2008). When sitting in front of the fireplace or bonfire, radiation is felt.

The guided inquiry lesson experiment is to teach about heat, temperature, and heat transfer. I put one cup of 120°F water in three identical ceramic mugs. The surface area of the open part of the mugs was 19.26 square inches. I covered the mugs with three different materials: clear plastic wrap, aluminum foil, and foam rubber. I sealed each of the mugs with a rubber band for 30 minutes. My hypothesis was that the foam rubber would be the best insulator, followed by the foil. I used a thermometer and measured the temperature of the water. I was surprised with the results. The best insulator was the foam rubber, but I would have thought it would have been hotter. It was 108°F. The other two had the same temperature, which was 106°F. It would appear that the loss of heat through the outer surface of the mug is a greater contributor to heat loss than the surface area of the top of the mug. I guess that’s why we use a handle to hold our mugs of coffee.

I would challenge my students by changing the variable being testing. For example, by using three different size mugs, with the same insulator, the students could investigate the loss of heat as a function of surface area of the mug. They would test if the area of the opening makes a difference with the amount of heat loss. Then, the students would create a bar graph to compare their results.

References

Banchi, H., & Bell, R. (2008). The many levels of inquiry. Science and Children, 46(2),

26–29. Use the Education Research Complete database and search using the article’s Accession Number: 34697743.

Tillery, B. W. (2007). Physical Science. (8 th ed.). New York: McGraw-Hill.

Tillery, B.W., Enger, E.D., & Ross, F.C. (2008). Integrated Science. (4th ed.). New York:

McGraw-Hill.

How does a pendulum work?

I started the guided inquiry lesson on pendulums by examining many materials. Inquiry-based approaches focus on students developing their own experiments as opposed to teacher-transmitted information (Banchi & Bell, 2008). I drew on my prior knowledge of how pendulums work and decided on using a fishing line, large paper clips, tape, wood doweling, ruler, and scissors. The Engage stage in the 5E model has students connect with past learning experiences and relate them to the present situation (Hammerman, 2006). I felt there was a missing component, which was the discussion stage. I did not have anyone to suggest different scenarios for testing by using the materials I had laid out. Students build on each other’s suggestions and perspectives, which is why I like to group or partner my students.

The next step was to create my experiment. This again is the next step in the 5E model called the Explore stage. During the reflective process, I actively constructed how I would investigate my inquiry by trial and error. I decided to tape my dowel between two desks. Since this kind of inquiry involves more student input than confirmation or structured methodologies, I had to choose the size of the weight, the length of the line, the height at which the bob would be released, and how far apart the desks would be. I had to make hypotheses and test my predictions. Even though in an inquiry-based lesson the teacher only provides students with the research question and takes a passive role, it would be an opportune time to inform the students how scientists could still learn from what happens in every investigation (Lantz, 2009). The students suggest many wonderful ideas to investigate. Some would work and some would not, but the teacher’s role would help teach students that scientists sometimes start over or design a new experiment when the data does not support the hypothesis. This process sparks additional inquiry. By acknowledging the similarity between what scientists do and what students do, I hope to promote an interest in STEM professions among my students (Lantz, 2009). As for my inquiry, I changed different angle positions. I investigated whether I could hold the bob directly above the hanger and get a smooth swing. I questioned if the pendulum would swing longer if it is released from a higher angle and at what angle would I get the longest period of swinging.

This led me to draw my conclusions. In a classroom, students would generate an explanation supported by the evidence they had collected (Banchi & Bell, 2008). In the Explain stage of the 5E model as well as in an inquiry-based lesson, students communicate and make sense of what they learned. The collaboration between peers and the teacher will further the understanding of the subject. Since I teach 3^rd grade, I need to address misconception as we summarize what is learned.

The Extend stage is for further inquiry to expand my knowledge. I decided to test two bobs at the same time by making one twice as heavy. I was interested in knowing whether they swung at the same rhythm or if the weight of the bob affects its swing. Then, I tested two of the same weight but shortened one of the lines. I found that one swing always moved more slowly. I also counted the number of swings each bob took with the help of a partner and observed which pendulum kept swinging longer. In addition, I made a connection to other related concepts. The wrecking ball is an example of the pendulum power. I even thought of Tarzan swinging from tree to tree. This would help the students understand the world around them in connection with the investigation.

The final stage is the Evaluation. I recommend using diverse assessments. I used a journal to write my questions as well as my observations. I even drew diagrams of how I would construct the different scenarios. Another type of assessment I would use to supplement or replace traditional formats is for the students to present their design and their findings to the class.

References

Banchi, H., & Bell, R. (2008). The many levels of inquiry. Science and Children, 46(2),

26–29. Use the Education Research Complete database and search using the article’s Accession Number:34697743.

Hammerman, E.L. (2006). Becoming a better science teacher: 8 steps to high quality

instruction and student achievement. Thousand Oaks, CA: Sage Publications.

Lantz, H.B. (2009). What should be the function of a k-12 STEM educator? SEEN

Magazine, 11(3).

Laureate Education, Inc. (Executive Producer). (2010c). Virtual Field Experience:

Science Lesson. The nature of science. Baltimore, MD: Author