Monday, May 21, 2012

The Heat Is On

Heat is defined as “a measure of the internal energy that has been absorbed or transferred from one body to another” (Tillery, 2008). This inquiry focused on the use of heat insulators and those that were more effective than others. During the course of this inquiry, I used polar fleece, wax paper, brown paper towel, and plastic wrap. I tried to vary my materials based on those that were transparent, translucent, and opaque, as well as those that I felt were able to absorb, release, or contain heat energy.

At the onset of the inquiry, I predicted that the plastic wrap would prevent the greatest loss of heat energy due to the lack of a porous surface. I chose not to test aluminum foil due to its known property of reflecting light and retaining heat. At the beginning of the inquiry, water was heated in a microwave for three minutes. It registered a temperature of 60° C. I made some initial observations as the water was poured into the four containers, and they were as follows: water vapor was observed as the water was poured into cooler containers and condensation immediately began to collect on the sides of all four containers. The containers were then covered and placed in the same location for thirty minutes.

When I returned to the containers thirty minutes later, I first recorded the temperature on each of four identical thermometers. Then I uncovered each glass container one at a time and measured the temperature. The first container with the polar fleece had a temperature of 23° C, the wax paper 38°C, the paper towel 39°C, and lastly the plastic wrap registered a temperature of 48°C.

When looking at the materials used, the level of transparency allowed for you to see the amount of condensation or lack of condensation that had collected on the top of the container. The materials themselves all had very different textures. The cloth can be said to have a very porous surface, thus it allowed the most heat to escape from the container. The wax paper had smaller pores in its surface which allowed less heat to transfer than the cloth. The paper towel had very tiny pores and retained even more heat than the wax paper. Lastly, the plastic wrap is perceived as air tight and therefore does not have a porous surface, so it retained the most heat and allowed very little transfer.

This inquiry was not difficult to complete. This would, however, be much more difficult to complete in my 5th grade classroom with small groups due to the water temperatures and the lack of proper safety equipment. My students would benefit greatly from watching the heat transfer process and understanding how insulators work to benefit them in their everyday lives.

Saturday, May 12, 2012

Guided InquiryUsing Marbles

"Momentum equals the mass of an object multiplied by its velocity." (Tillery, 2008.) During this guided inquiry, I tested Newton's second law of motion. He stated that, "the relationship between the net force, acceleration, and mass that describes the cause of change in motion." (Tillery, 2008.

The focus of my guided inquiry was, "How do different surfaces affect the momentum of marbles?" (Laureate, 2012.) I designed an inquiry involving an inclined plane, two marbles of different masses, a ruler, and multiple surfaces for the marbles to cross during the investigation. The first part of the inquiry involved testing both marbles with a plain surface to demonstrate how the marbles acted without increased friction. Next, the marbles were released at coinciding times and travelled across the different surfaces and observed for any differences based on the increase of friction and surface.

The marble with the smaller mass travelled faster than the one with the greater mass over the plastic wrap. They both travelled equally as far over the plain paper, aluminum foil, and the plain surface. The marble with the greater mass travelled a further distance over the foam, cardboard, wax paper, and the polar fleece. I believed that the marble with the smaller mass would slow down as it passed over the foil, foam, and plastic. I also believed that the marble with the smaller mass would stop not far it began to travel across the fleece.  The results were not as expected with the marble with the smaller mass. I believed that there would be more friction present in all the materials. The majority of the inquiry went really well. The one thing that was a struggle was releasing the marbles at the same time to ensure that the same result would occur. To get the desired results, I tested each marble run three times.

If I were to repeat this inquiry, I would try to design a device that would include a gate that opens at the push of a lever in order to control the equal release of the marbles.

I would have prototype models available in a variety of ways to allow students the ability to create their own design. It may help them to visualize the direction they need to move in order to be successful. The students would be provided with a scenario regarding a new ramp that is being built from the highway into their school parking lot. The students job would be to decide which type of surface would slow traffic and create more friction to prevent speeding coming off the ramp into the school.

I would like for my students to gain an understanding of friction's affect on momentum and how friction can have positive benefits in their daily lives. Most of the time we talk about friction slowing us down in a negative way, but I want them to see it has benefical uses also. Yes, I think I did achieve this goal.