Hot Hot Hot!

Oh this week I had a blunder!!!  Instead of just heating the water to a warmer temperature for our experiment, I BOILED it.  THEN I decided to place the thermometer in.  Big mistake!!!  The thermomtere IMMEDIATELY exploded and I had to head back to school and grab a thermometer from my supplies!

I chose foil, plastic wrap, a shirt and a piece of paper to test as insulators.  The heat energy in the water was moving through the air via radiation.  These materials were being tested to see which one best slowed down that process.  To my surprise, the shirt was the best insulator, however, it did become saturated with water that evaporated from the mug. 

When I got this result I immediately starting thinking about different types of clothing and how they keep us warm.  I would like to test out a sweatshirt, a t-shirt, a pair of jeans  and a long sleeve shirt.  I imagine that the sweatshirt and or jeans would be the best insulator because they are a much thicker material and there is less space for the molecules to move through.  I might test my body surface temperature if I did this experiment again.  I'm not sure if that is possible, but it would be fun to try!

I would set this up with some sort of food that the students eat everyday.  Pizza maybe, and heat it up to a certain temperature in the beginning of class, have the students wrap it in different materials and in different sizes, or place it in different containers and have them hypothesize what the outcome would be.  We could then get into a discussion about how the cafeteria keeps our food warm and the different ways that this could happen.

I would want students to understand that different materials will act better as insulators than others.  By doing the experiment with the water in the mugs I was able to confirm why I place foil over food to keep it warm.  It also got my brain thinking about the different types of clothing I wear according to the weather.  I think that by having the students see the results of the pizza or food experiment they would be able to see that different materials are better suited for acting as an insulator than others.

Watch Out For That..........!!!

This week I set up an inquiry lesson for myself to try out!!  I wanted to try and answer the question "How does the steepness of a slope and mass affect a collision outcome?".  Seeing that my last physics class was taken about 8 years ago I was fumbling around a bit until I settled on the design that I was happy with.  Physics and I have never gotten along, apparently my brain thinks the exact opposite of physics concepts and that makes it hard for me to understand the concepts. 

I set up my experiment as such: a small marble (7g) trial and a large marble(23g) trial.  I tested three different slopes three different times.  The more data I can collect will give me a more reliable answer.  I placed a three composition notebooks on top of each other, and took a ruler to create the slope that the marble would travel down.  At the bottom of the ruler was a toy car.  I placed the marble at the same place on the ruler EVERY TIME to take out that variable.  Once the collision had occurred, I measured the distance the car traveled and the overall disruptions of the car. 

I saw a difference in the distance the car traveled and overall disturbance of the car in the large marble trials.  The small marble did not do much damage, even when the slope was increased.  I had expected to see changes in the collision with the large marble trials, but also expected to see a difference in the small marble trials.  I was disappointed when that did not happen, but then I stepped back and started to think.  The marbles were not traveling a long distance.  Maybe next time I would increase the distance that the marbles traveled and that would give them more time to pick up more speed?  I also have to keep in mind that the longer distance they travel, the more friction they would incur as well, which can slow down speed. 

I would like to set this up in my classroom towards the end of the year.  Since I teach Life Science it will be hard to fit it in before our "free teaching time" at the end of the year.  I think many of my students will enjoy a hands on inquiry such as this, and I would have them graph their results and see if  every group had the same outcome.  This could lead into a great discussion of controls and variables.  Actually, this might be a good way to introduce controls and variables in the beginning of the year, it is something that students continually struggle with and looking at it hands on would be a great way to help them understand!