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.

Reflection

One structured inquiry lesson I implemented this year was called the Sugar Race.  This lab focused on the concept of rate of reactions.  To start off my lesson I told students that they were eating at a restaurant and wanted sweetened tea but the restaurant only carried unsweetened tea.  I asked them how would they sweeten their tea and what methods might work the best.  This introduction really grabbed the attention of my students because about 90% of them had been in this type of situation.  I then had my students design an experiment to see what factors would affect how long it took for the sugar to dissolve.  My students used the scientific method to help them during this process.  Students were testing to see if the amount of water, temperature of the water, size of the sugar cube, and type of water affected the rate at which the sugar dissolved. The results from their experiments were that high temperatures increased the rate the sugar dissolved better than any other method.  The other factors that affected the way the sugar dissolved were crushing  and stirring the sugar cube.
Overall, I believe this lesson was successful.  My students met the objective and were focused throughout the entire experiment.  I observed students asking questions and curious about their results and observations.  I witnessed team work during this activity where students took responsibility for their role in the group. I also enjoyed the meaningful discussion at the end of the lesson which confirmed students reached the goals for this assignment. Additionally, I identified areas that needed improvement .  I would like to improve on the time it takes to complete this assignment by giving students options to choose from instead of them creating new ideas.  With this in place the activity would be completed in two days rather than almost four.  I would also have students evaluate each other during this activity to ensure every student is on task and actively learning.

Global Warming?

The main issue concerning global warming is if it is truly happening or not.  Many people believe that global warming is a myth and that at certain periods the world goes through these types of changes.  Other people believe that the polar ice caps are melting and this occurrence will eventually flood different areas around the world.  In week 3 of my class, we were asked to melt ice cubes in water using a cup to see what happened to the volume of water.  Not thinking about the principle of displacement, I immediately thought that it would spill out of the cup.  This of course did not happen. From what I could see the water volume stayed the same.  This again was because of water displacement. Unfortunately, I cannot use this experiment to conclude about the affects of global warming because I think there are other factors to consider.

Science lesson

This week's assignment was interesting.  Normally when I create my lessons I do not go through such an intense process.  I believe this assignment made me analyze every part of my lesson to make sure it is effective in the classroom.  The lesson I created was about the changes of state.  I assigned groups of four one change of state and they researched and learned about it.  After gathering information, each group designed an experiment to demonstrate that change of state.  For instance, one group that was assigned sublimation used dry ice to show the change of state.  I thought the 5 E strategy was very helpful in that it guaranteed an active learning environment.  I think I am going to start using this strategy when I develop future lessons.  One thing I would change about the lesson is the time it would take to complete it.  This lesson would normally take about 2-3days.  To shorten the time, I could have a list of possible experiments my students could conduct instead of them creating their own.  I hate cutting their creativity, but I believe this modification would help the lesson flow better.