The Heat is On

This week my focus for guided inquiry was which material was the best insulator.  I chose plastic wrap, aluminum foil, a kitchen towel, and notebook paper to test my question.  My hypothesis was that the aluminum foil would be the best insulator and notebook paper would be the worst.  I chose aluminum foil because many baking pans are made out of aluminum.  My thinking was that they helped disperse the heat evenly and held in the heat to help food cook.  I knew notebook paper was very thin, making it a poor insulator.

I began the experiment by lining up four mugs that were exactly the same on the counter.  I measured and placed a line inside each mug to ensure that I had the same amount of water in each mug.  I then heated the water to boiling in a tea kettle.  This allowed me to know the exact starting temperature of the water.  Once the water began to boil I immediately poured it into the mugs, and quickly placed each material on top, securing it with a rubber band.  I waited thirty minutes then used a thermometer to check the temperature of each mug of water.

I found that the kitchen towel was the better insulator.  This makes sense, though, many people wrap casserole dishes in towels to keep them warm.  I was correct in thinking that notebook paper was the worst insulator. 

I would love to test this with macaroni and cheese.  I have a two year old niece who loves macaroni, and I feel that it takes forever for it cool off.  I believe that pasta, due to its consistency, may stay warmer longer than water.  This may be my next experiment.

Losing my Marbles

This week I investigated how different surfaces affect the momentum of marbles.  I chose to roll one large and one small marble on the hardwood floor, a  fleece blanket, an area rug, and a tile floor.  I expected to find that it was easiest for the marbles to roll across the hardwood floor and hardest for them to roll across the rug.  My findings were pretty much what my initial thoughts were. 

At first I wanted to make sure that the size of the marble did not affect the experiment results.  It was very difficult for me to figure this out.  I had difficulty ensuring that I used the exact same amount of force on the marbles when rolling them.  If I were to conduct the experiment again I would use something that would apply a consistent force for all the surface areas.  I am having some difficulty deciding on the best approach to doing this.

If I were to conduct this experiment with students I would have some students place the blanket over different surfaces as well without discussing that differing variable.  Then we could discuss what why the results were different with the blanket.  This could lead to great conversation, and help students apply their new knowledge.

To make this experiment more fun for my students I could conduct a marble race.  Students could pick which surface they want to race on.  I could also place a target in the floor and see if students could cause the marble to stop in the middle of the bulls-eye.  This could make the experiment more engaging and fun for the students, and help them to see that you need to apply different amounts of force depending on its rolling surface.  They can also learn that different amounts of friction are placed on the marble based on the rolling surface as well.  This would be a great experiment for second graders.