The content area I chose for this week’s assignment is simple machines. Looking for 21st century tools that would assist my students in learning about this topic; I decided to approach the assignment, as “how would I teach the students the concept using only web or technology tools?” To introduce the topic of simple machines the video on Rube Goldberg machines http://www.youtube.com/watch?v=qybUFnY7Y8w will awaken their interest and motivation. Then the explanations at http://aspire.cosmic-ray.org/labs/machine/act1a/index.html to support their basic understanding of simple machines. Next students see a historical perspective and perform various activities in the Inventor’s Workshop http://www.mos.org/sln/Leonardo/InventorsWorkshop.html. Going through the activities in the Inventor’s Workshop will generate questions they may want to answer and they develop and understanding of how others in the past solved everyday problems. Once they have looked at these activities and experiences they need hands on classroom activity where they test some basic simple machines collecting and comparing data to see if the machines actually help reduce the work. The last station of this is the computer with the http://www.edheads.org/activities/simple-machines/, this site brings everyday objects around the house and helps students identity them as simple machines. The culminating activity is collaborative groups to create a short video using http://goanimate.com/ to summarize their learning. If, the students are advanced enough they may take on the challenge of entering a Rube Goldberg contest http://www.rubegoldberg.com/
Friday, February 17, 2012
Heat as Energy - Week 4 Course V
For your blog entry this week, think like a scientist, and reflect on the heat transfer experiment you conducted in the Application. Describe the materials you selected for the experiment, and explain why you chose them. Share the results of your experiment. Which materials made the best insulators?
The materials I decided to test were wax paper, aluminum foil, plastic wrap, and a cotton kitchen towel. The reason I selected these materials is because I felt all of them had the potential to be good insulators. Based on the data gathered, my analysis showed the best insulator of this group of materials was the kitchen towel.
The three methods of heat transfer are conduction, convection, and radiation. Convection is a form of transfer where currents are used to move heat. Since all of the containers in this experiment were covered, this method was discouraged. Radiation would also include the movement of heat from the container to the surrounding area once again discouraged by the tight cover. The one method that was encouraged by this experiment was conduction since it is based on heat transferring by touch of one surface to the other. The liquid touches the cup, it touches the counter, and the cover placed on it allowing the heat to move.
If I were to perform this experiment, again I would use the cotton kitchen towel, a rubber matting, aluminum foil and a lighter fabric such as silk. I think the rubber matting would be the best insulator because the rubber would be molded and does not breathe as the cotton does.
I would not be interested in testing other materials, simply because they would be messier to deal with in a classroom setting. But, I think any material that is layered such as hot dogs or spaghetti would keep their heat longer than water, because the transfer has to progress through layers. To make this experiment connect to real life experiences rather than just “materials” I would try to find actual items such as the plastic cover on the coffee cups, the can shaped insulators, paper cup covers from the hotel rooms. These items are familiar and knowing which one insulates best would be beneficial if they were going to purchase any of these.
This is a great lesson to learn about conduction and insulators all in one. In performing the experiment I had to think about these two concepts, in my mind this makes it the proper tool to teach them.
The materials I decided to test were wax paper, aluminum foil, plastic wrap, and a cotton kitchen towel. The reason I selected these materials is because I felt all of them had the potential to be good insulators. Based on the data gathered, my analysis showed the best insulator of this group of materials was the kitchen towel.
The three methods of heat transfer are conduction, convection, and radiation. Convection is a form of transfer where currents are used to move heat. Since all of the containers in this experiment were covered, this method was discouraged. Radiation would also include the movement of heat from the container to the surrounding area once again discouraged by the tight cover. The one method that was encouraged by this experiment was conduction since it is based on heat transferring by touch of one surface to the other. The liquid touches the cup, it touches the counter, and the cover placed on it allowing the heat to move.
If I were to perform this experiment, again I would use the cotton kitchen towel, a rubber matting, aluminum foil and a lighter fabric such as silk. I think the rubber matting would be the best insulator because the rubber would be molded and does not breathe as the cotton does.
I would not be interested in testing other materials, simply because they would be messier to deal with in a classroom setting. But, I think any material that is layered such as hot dogs or spaghetti would keep their heat longer than water, because the transfer has to progress through layers. To make this experiment connect to real life experiences rather than just “materials” I would try to find actual items such as the plastic cover on the coffee cups, the can shaped insulators, paper cup covers from the hotel rooms. These items are familiar and knowing which one insulates best would be beneficial if they were going to purchase any of these.
This is a great lesson to learn about conduction and insulators all in one. In performing the experiment I had to think about these two concepts, in my mind this makes it the proper tool to teach them.
The Pendulum - Week 2 Course V
The question I chose to investigate in week 2 of the course was “Which pendulum will come to rest more quickly—a lighter pendulum or heavier pendulum? The procedure I designed was:
1. Cut a piece of string 30cm
2. Tie a large washer to the string
3. Using a push pin secure the string to a piece of card board
4. Lift the string to one of the sides so that it is perpendicular to the pin and hold it
5. Start a stop watch as you release the washer
6. Record how long it takes for the washer to stop
7. Repeat steps 4-6 an additional five times
8. Remove the large washer and Repeat steps 2- 7 using a small washer
The results were as I expected given pendulum with the lighter mass took longer to stop meaning it had more acceleration. Although they are released with the same force the
A= F/m, the larger the mass the slower the acceleration. To obtain a different result instead of a washer I would use an object with a different shape such as a flat piece of wood and tie it so the surface area could play a part. I believe giving the object with less mass a larger surface area would change the outcome of this experiment.
Using the pushpin was not as successful as I thought; I ended up having to repair the pushpin hole with tape several times.
I would use this experiment with my students but if my idea of using the wood to add the effect of air resistance, I would make them run it with the two types of material. I would do this without introducing air resistance in my lecture hoping they would discover it on their own.
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