The Heat Is On

This week I conducted an experiment on heat.  I poured 50 ml of water into four coffee mugs.  The water was heated to 48 degrees Celsius. I then placed different materials over the top the each mug.  The four materials used were foil, cloth, plastic wrap, and wool.  I let the mugs sit for 30 minutes and then took the temperature of each mug. 

My results were a little surprising.  Before I completed the experiment I thought that the wool would be the best insulator because it was the thickest material  and most clothing used in the winter is made of wool.  I thought the plastic wrap would be the worst insulator because it's typically not used to retain heat.  People use plastic wrap to cover cold items. The results of my experiment were the cloth had the highest temperature, then the foil and wool were tied in second, and the plastic wrap was the worst.

If I were to repeat this experiment I would like to use different materials as insulators.  I would like to use Styrofoam and cotton.  Styrofoam is used in coffee cups to keep the coffee warm but also to make the cup cool to the touch. Cotton is a thick material that is used in clothing to help people maintain body heat. I think the Styrofoam will be the best insulator and reduce the amount of heat that escapes.

I think this experiment would be great as a take home experiment for my students.  During the school year I have my students complete about four take home experiments.  It would be nice for my students to complete this activity at home and find different materials to test.  Parents, of course, would help with this activity.

How different surfaces affect the momentum of marbles

A couple of weeks ago I conducted an experiment about how different surfaces affect the momentum of marbles.  I used one marble and tested the marble on three different surfaces: concrete, hardwood, and carpet. To make it fair between surfaces, I created a ramp for the marble to travel down before coming in contact with the surfaces.I made my ramp out of a textbook and Popsicle sticks

 The results of my experiment were that the marble had the most momentum on the hardwood and the least momentum on the carpet. An explanation of my results would be that the hardwood floor created the least amount of friction, which allowed the marble to travel farther and at a greater speed.  The carpet has more hills and valleys in it which increased the amount of friction.  The concrete also had a rougher surface. The results I received were what I expected.

I encountered some challenges during my experiment.  One of the challenges I faced during this experiment was keeping the marble rolling in a line down the ramp.  I decided to use Popsicle sticks to help keep the marble down a straight path.  Another challenge I faced was measuring the distance the marbles rolled.  At school I have access to yards sticks, but at home only a couple of 12 inch rulers.

I would like to use this activity in the classroom next year.  To make the lesson more interesting for my students I would use toy cars and allow them to make their own ramps.  I would also let them test the experiment on the surfaces we have at school and their homes. This allows parents to get involved in their child's learning.

The purpose of the lab is to introduce students to momentum. I would like students to understand that different surfaces do affect the momentum of objects and be able to apply what they learned to their lives. As an assessment I would have students explain how they could apply their knowledge to their lives to help them in a situation.