Heat engines are a standard for AP physics and for STAR. The meat of the standards is simple calculations involving heat added, work done, heat rejected, input temperature, output temperature and theoretical and actual efficiency.
I decided to write up a case study on heat engines that can be found here:
https://sites.google.com/a/sduhsd.net/brinn-belyea-science-teacher/home/ap-physics-b/units-of-study/unit-5-fluid-mechanics-and-thermodynamics/heat-engines-case-study
I assigned the students to read the case study and visit the links. In class I showed a few diagrams of engines and asked for questions. I then had the students do the case study questions. I used technology to post the case study to google docs and to find information for the study.
I also invited Kevin Fairchild, the district teacher on assignment for technology, to observe.
The key to this case study is the questions. The questions were designed to test in depth knowledge of heat engines but also incorporate fluids and other physics topics.
We were on a late start day so we were unable to have every group of students finish the case study questions in class. Instead of going over them that day we will go over the questions to start discussion the next day.
Some observations I made:
1. One group of students had trouble staying on task. One of the students had a pad of some sort and was on the wikipedia page for the Blackswift top secret aircraft. He told me he got there from the wikipedia page on the Blackbird aircraft which is one of the case study questions. I later looked over this group's answers and found some weak responses.
2. The speed at which students proceed through the questions varies greatly. I notice that some seniors move slowly as they're not so interested. Others see it as a respite from the normal work focused intensely on standards such as problems that start "A heat engine inputs 3000J at 1500K...." The juniors and sophomore tended to proceed faster so that they could get to the book problems that more directly impact their grades. One group of juniors was quite slow but this is a general motivational issue.
3. The issues students had with questions ranged from gaps in basic knowledge of standards to lack of ability to read the question to lack of ability to explain what they had in their head to struggling with conceptual knowledge.
My reflection on the observations:
1. It feels good to stimulate interest in STEM because that's why I became a teacher. On the other hand we get reminded of the need to be on task etc. because of the all important testing. I think some of the weak responses of this group are laziness, others reveal a lack of understanding of the material.
2. I made sure to have something for the kids who finished early. In general I didn't detect a big difference in relative motivation between different students on the case study vs regular work but an overall higher level for all on the case study.
3. I like the fact that this assignment stresses the entire structure of a student's understanding of physics. I think this type of assignment, when done in groups is a powerful tool for differentiated instruction as gaps in all areas can be exposed and the students can help each other fill those gaps. Working book problems, labs, etc usually only hit one or two areas of understanding.
Kevin was very helpful during and after the case study. He walked around and helped me answer student questions during the activity. Afterwards we spoke by phone. Kevin suggested I incorporate student presentations to get across some of the basic knowledge bits. This would reinforce the nonfiction reading parts of the common core standards.
Overall, I want to keep doing case studies in chem and physics. The evidence says that engagement is higher and that it helps teach higher order thinking.
