SCIE-6661S-1 Exploring the Physical World---Week 4 Scientific Inquiry: Choosing Insulators

 

When selecting materials to test as insulators I considered the common items in my home and their uses.  An insulator is a material that prevents heat from escaping, keeping items warm for longer periods of time. Insulators have many common uses in the home from building materials to food containers.  Depending on the job of the insulator the materials used to insulate can vary greatly.  Why do we spend time investigating insulators you may ask?  With a lot of emphasis being placed on buildings being energy efficient research into the economic benefits of maximum insulators has become an important topic (Tillery, Enger, & Ross, 2008).  

In my experiment I chose four common household items and tested their insulating potential.  I chose to test plastic wrap, aluminum foil, newspaper and cotton cloth.  I believe that if I test all four if my insulators then the foil will prove to be the most efficient in the retention of heat.  In order to test my insulators I used four 200 milliliter beakers, water heated to sixty five degrees, rubber bands and Fahrenheit thermometer.  After pouring 100 milliliters of heated water into each beaker I secured my insulators over the beaker opening with a rubber band.  After a thirty minute cooling period I measured the temperature of the water in each beaker again, recording the difference.  After conducting three trials for each of my insulators I averaged the results.  I found that my choice, foil being the best at insulating, was correct.  The average temperature change for each of my insulators is as follows.  The plastic wrap experienced an average drop of 35 degrees, the aluminum foil experienced an average drop of 12 degrees, the newspaper experienced an average drop of 29 degrees, and the cotton cloth experienced an average drop of 31 degrees.  I expected the foil to be the most efficient at insulating; having knowledge of its common uses and properties indicated its ability to hold heat in effectively.  I hypothesized that the plastic wrap would have been a close runner up to the foil and was very surprised that its ability to retain heat was so poor.  I did not believe that the cloth or newspaper would act as good insulators in this case and was not surprised at those results. 

This activity was very easy to prepare and execute in a classroom.  I can see my students being able to replicate this activity in the classroom and gather similar useful data.  It would make for an interesting topic in our classroom discussions.  I would be very interested to hear their opinions as to which items they would chose as best insulators and why the others would not.  Sometimes students’ clear, unrestricted views make more sense than our preconceived ideas.  I would also like my students to choose materials they feel would be good insulators and execute the same test for them.  After the students analyze their data and compare all the results an open forum of conversation would be enlightening on their choices and results.

 

 References

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

McGraw-Hill

    

SCIE-6661S-1 Exploring the Physical World---Week 3 Scientific Inquiry on Electromagnetism:

 

When researching methods of creating an electromagnet there were several variables to consider and test.  Electromagnets can be turned on and off by using a battery as the source of electrons. By connecting a wire to the battery you create a flow of electrons through the wire, there must be a complete circuit for the electrons to flow. In doing this you cause the electrons to behave like a magnet when they flow through the wire, creating a magnetic field.  Every electric charge is surrounded by an electric field.  If the charge is moving, it is surrounded by an electric field and a magnetic field (Tillery, Enger, & Ross, 2008).   

In my design I chose to test two different variables that could increase the electromagnetic flow of my magnet.  My first variable tested was how the amount of coils in the wire affects the strength of the magnet.  I believe that if I increase the number of coils then the magnet will be stronger.  I began my experiment by creating the magnet without any coils in the wire and recording the amount of paperclips collected.  I chose to add five coils at a time, with a maximum of twenty, and test each addition of coils three times.  I found that as I increased the amount of coils in the wire the magnetism increased.  With each addition of five coils in the wire the amount of paperclips attracted increased.

With my first variable tested and the data recorded I moved on to my next variable.  In my next experimental design I tested the gage of the wire and its effects on the strength of the magnet.  I believe that if I increase the gage of the wire then the magnetism will decrease.  Using the two different gauges of wire provided in our kits I created the first magnet with the thinner gauged wire.  During the three trials for the thin gauged wire the paperclips collected by the magnet were consistent, picking up five paperclips each time.  After changing to the thicker gauged wire and conducting the experiment again I noticed that the paper clips attracted to the magnet were inconsistent but approximately the same.  The amount of paper clips attracted to the magnet with the thicker gauge wire ranged from four to five at a time.  I concluded that the gauge of the wire had very little to no effect on the strength of my magnet.

As I read up on magnetism in our course text and prepared and then executed my experiment I was reminded of why we allow students to design their own procedure and why we provide procedure.  I some cases students have no experience with the materials they are testing, in other cases they have had exposure.  Most students have had exposure to magnetism at an early age. I do not know many, if any, children that have not enjoyed playing with magnets at some point in their youth.  If I were to conduct this experiment with my students they would ultimately ask why we would need to try to increase the magnetism so many different ways.  I would remind them that different designs are used for different applications (Tillery, Enger, & Ross, 2008).  Our job, as scientists, is to investigate all the possibilities and find the results.      

 

References

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

SCIE-6661S-1 Exploring the Physical World---Week 2 Guided Inquiry---Surface affects Momentum

 

In my chosen guided inquiry I selected how two different surfaces affect the momentum of a marble? My hypothesis is if I compare the linoleum floor to the carpeted floor in my school hallway then the momentum of the marble will be faster and go further on the linoleum. For my experiment I used the large marble, a meter stick, linoleum, and carpeted hallway flooring. For each trial, I tested each surface three times, I averaged the results. I marked the floor with tape and rolled the marble in the designated area.  The following are my results: on the carpeted floor the average distance was 12 centimeters, and on the linoleum the average distance was 52 centimeters. Based on prior knowledge I knew that the carpet would cause friction and imped the speed and distance of the marble. When assessing the floors the carpets texture looked rougher in comparison to the linoleum indicating to me a possible impairment in momentum. Challenges I encountered during my experiment were minimal with the exception of keeping the marble in the defined boundary. If I chose to do this experiment in the classroom I would consider creating a track with different surfaces. This would eliminate the problem of the wandering marble.  

This experiment is a good example of guided inquiry for students. My students will have the opportunity to learn how to independently inquire, use data, and adapt design to accommodate problems. With my 8^th grade students I can associate the surface to possible concerns for road surfaces when they become drivers. To give more opportunity for the students to explore perhaps we could test other surfaces around the school. During state standardized testing Newton’s laws are addressed. We spend time before the test reviewing concepts learned in prior years and this activity would be an excellent way to review the laws and see where they apply.