LESSON 2: (Approximately 3.5 hours; two 2-hour class periods)
THE ECONOMIC & HUMANITARIAN FACETS OF SOLAR OVENS
Overview
Materials
‘YouTube’ Non-parabolic solar oven
Digital projector Student and teacher laptops
Projector screen 'Skype’
Word processing program (e.g., ‘Google Docs’) ‘Microsoft Excel’
Graph paper ‘Popplet’
Blank white paper Scientific or graphing calculators
Colored pencils and pens Sticky notes
Parabolic satellite dish
Community Resources
Energy experts (e.g., electrical engineer and post-doc in cellular biology)
Key Words
Fossil fuels | Solar energy | Green energy | Solar ovens/solar melting devices | Parabolas | Paraboloids | Dilation value | Focus/Focal length | Watt | Joule | Project-based learning | Robust teams
TEACHING PLAN
Introduction
“Life’s most persistent and urgent question is, ‘What are you doing for others?’”
--- Dr. Martin Luther King, Jr.
Today we will focus our growing knowledge of parabolas and quadratic functions into a humanitarian and economic study. As mentioned last class, we will begin to design the parabolic solar ovens that we will build next class. Today, we will delve into the significance of these solar ovens: their potential benefits to communities both local and abroad, how we might engineer them for various cooking needs, and some of the challenges associated with building parabolic solar ovens and utilizing solar energy. We will speak with energy experts via ‘Skype’ so feel free to ask them any questions you think of. Finally, we will randomly assemble ourselves into design teams and begin planning for next class. For those interested in digital drawings, we will be using the computer program ‘Rhinoceros’ to render the unique parabolic solar ovens we will construct. I am eager to begin working with each of you! Do you have any questions?
ASK Questions and discuss as a class (10 minutes)
Task
Wrap Up
Discuss
Distribute
Web Resources
Formative Assessments
Summative Assessments
THE ECONOMIC & HUMANITARIAN FACETS OF SOLAR OVENS
Overview
- Evaluating videos documenting fossil fuel use and some of their hazards (especially in developing nations)
- Anticipating challenges associated with the fuels most often used in developing nations
- Analyzing why solar melting devices can be robust forms of humanitarian aid
- Evaluating the strengths and weaknesses of parabolic versus non-parabolic melting devices
- Analyzing the physical and mathematical underpinnings for why parabolic solar ovens are ideal for generating high temperatures at a point or along a line
- Applying mathematical knowledge of the focal point to paraboloids and parabolic troughs
- Arguing for various parabolic design uses under various circumstances
- Modifying student group designs to solar ovens to serve specific humanitarian purposes
- Predicting specific uses for students’ solar melting devices in their own community
- Asking experts questions about fossil fuel and solar energy
- Estimating the cost of solar melting devices/solar ovens
- Using ‘Popplet’ to organize team materials to purchase/use in the construction of a parabolic solar melting device
- Anticipating several design and functionality challenges associated with constructing and maintaining effective parabolic solar melting devices
Materials
‘YouTube’ Non-parabolic solar oven
Digital projector Student and teacher laptops
Projector screen 'Skype’
Word processing program (e.g., ‘Google Docs’) ‘Microsoft Excel’
Graph paper ‘Popplet’
Blank white paper Scientific or graphing calculators
Colored pencils and pens Sticky notes
Parabolic satellite dish
Community Resources
Energy experts (e.g., electrical engineer and post-doc in cellular biology)
Key Words
Fossil fuels | Solar energy | Green energy | Solar ovens/solar melting devices | Parabolas | Paraboloids | Dilation value | Focus/Focal length | Watt | Joule | Project-based learning | Robust teams
TEACHING PLAN
Introduction
“Life’s most persistent and urgent question is, ‘What are you doing for others?’”
--- Dr. Martin Luther King, Jr.
Today we will focus our growing knowledge of parabolas and quadratic functions into a humanitarian and economic study. As mentioned last class, we will begin to design the parabolic solar ovens that we will build next class. Today, we will delve into the significance of these solar ovens: their potential benefits to communities both local and abroad, how we might engineer them for various cooking needs, and some of the challenges associated with building parabolic solar ovens and utilizing solar energy. We will speak with energy experts via ‘Skype’ so feel free to ask them any questions you think of. Finally, we will randomly assemble ourselves into design teams and begin planning for next class. For those interested in digital drawings, we will be using the computer program ‘Rhinoceros’ to render the unique parabolic solar ovens we will construct. I am eager to begin working with each of you! Do you have any questions?
ASK Questions and discuss as a class (10 minutes)
- After submitting homework, consider this question: On average, each day the sun delivers approximately _____ Watts (a unit of power; one Joule per second where Joules are a unit of energy) per square meter that reach the surface of Earth from the sun. This is enough to power _________, _________, or ___________. Across the entire surface of the Earth, this is on average _____ times as much energy as is used each second worldwide.
- How can our knowledge of parabolas and paraboloids serve our community?
- How is solar energy being utilized today and how might it be used in the near future?
- What materials are needed for constructing a parabolic solar melting device?
- How economical (i.e. affordable) are solar melting devices?
- What are some potential economical and humanitarian ramifications of building solar melting devices?
Task
- If you were asked to describe the relationship between dilation value and focal length to underclassmen, how would you go about doing it? Please highlight your ideas with words and diagrams on the butcher paper taped to your desk. Afterwards, walk around the classroom and look at other classmates’ ideas. (5 minutes)
- Watch three subtitled videos documenting fossil fuels, their usage, and challenges (11 minutes)
- “Fossil Fules 101”
- “300 Years of Fossil Fuels in 300 Seconds”
- “Appropriate Technology Gains Ground in Developing Countries” (first two minutes)
- In groups of two, consider challenges associated with using the fuel sources most commonly used in developing nations. Post your ideas to your desk using the sticky notes provided. Quickly get up and survey the ideas written by your classmates. (5 minutes).
- As a class, discuss some of the themes expressed in the video and student writing. (5 minutes)
- With a new partner, juxtapose the benefits and drawbacks of using solar energy as a fuel source in developing nations paying close attention to parabolic and non-parabolic solar melting devices. Post these ideas once more to a desk. (5 minutes)
- Discuss: What are some of the benefits and hurdles to parabolic and non-parabolic solar melting devices being distributed and utilized in developing nations? (10 minutes)
- Dynamic stretch break: bilateral stretches (2 minutes)
- Head outside and inspect the two parabolic satellite dishes as well as the two non-parabolic solar ovens. Feel free to pick them up, move them, and criticize the strengths and weaknesses of their design. (7 minutes)
- Meet with a classmate with whom you have not interacted much in the past two class periods. Together, list some scenarios that call for a parabolic solar melting device and scenarios that call for a non-parabolic solar oven. Be prepared to defend your decisions using mathematical terms, diagrams, etc. (5 minutes)
- On a shared ‘Google Doc’ contribute the ideas you and your partner developed in ¾ to 1 page of a double-spaced page. You and your partner may complete one copy. Once completed, submit your ideas and make sure to share the Google Doc with me. Be sure to identify whose ideas are whose on the Google Doc by putting your names next to your contributions. (10 minutes)
- As a class, we will now log on to ’Skype’ and engage in Q & A with two energy experts: one from San Diego Gas and Electric (SDG&E); an electrical engineer, and one from J.Craig Venter Institute (J.C.V.I.); a post-doc in cellular biology with expertise in solar energy and algae. Please remember to be courteous ambassadors of our school and make sure to gather answers to those amazing questions you have been formulating today! (20 minutes)
- Discuss: What did we think of the experts and their ideas? How can we use the information we gleaned from these discussions to inform our upcoming design of parabolic solar melting devices? (7 minutes)
- Write your name on a small piece of scratch paper and place this paper on the teacher’s desk. We will now randomly make student teams of four. In your team, you will be making a parabolic solar melting device. Although we have investigated both non-parabolic solar ovens and parabolic solar melting devices, we will be designing and building unique parabolic melting devices explicitly. (3 minutes)
- Find your teams somewhere in the classroom. Be sure to take your math portfolios and pencils with you. Create a team name! (3 minutes)
- Brainstorm some design ideas for a parabolic solar melting device with members of your team before signing on to ‘Popplet’ and organizing your ideas as a collective, team mind map. Please make your ‘Popplet’ shared and viewable to all. (20 minutes)
- Stretch break: Trunk twists and ‘flamingos’ (1 minute)
- In a team discussion, identify the strengths and weaknesses of your design ideas within your group. Remember to use compassionate, constructive language with your teammates. The more ideas you can generate the better! (7 minutes)
- Using the internet, price out the cost of your parabolic solar melting device. Keep in mind the classroom budget per group is $25. Anything above this will require spending your own money. Consider avoiding excessive cost. (20 minutes)
Wrap Up
Discuss
- In two class periods, we will begin constructing our parabolic solar ovens. Two outside experts will be on hand to assist you: A school volunteer and retired mechanical engineer and an architect and expert woodworker. I will also be available to help you and will be meeting with groups throughout the class period. We will have access to the Innovation Lab where we can use saws, drills, hammers, etc. (2 minutes)
- Right now, within your groups, decide which team member will… (5 minutes)
- communicate your team’s wish list of materials for next class
- draft three schematic drawings of your first design idea and bring it to class next time
- serve as coordinator of team activities next class and
- who will serve as recorder/photographer next time.
- I will do everything I can to purchase requested materials at Home Depot or similar stores around town. Please remember that we will be completing two iterations of designs so consider saving some money to spend on your second design. (2 minutes)
- Review homework deliverables due next class: (10 minutes)
- Download the link to Rhino and start to explore the software.
- Optional: Work through a ‘Rhinoceros’ tutorial about rendering sketches in the digital realm.
- Within assigned teams:
- Materials Team Member: Create a document communicating your team’s wish list of materials to me. Please include the price of each item as well as the quantity of items you will need. You will not need to purchase screws or nails. You will also be responsible for ensuring safe lab practices and cleaning up equipment and tools during construction.
- Schematics Team Member: Draft three schematic drawings of your team’s first design idea. Do not worry if these are beautiful drawings. Sketches only need to be useful in building a three-dimensional parabolic melting device. It will also be your responsibility to ensure that the solar oven has been built to the specifications of your drawings.
- Coordinator Team Member: Create a list of tasks for individual team members to complete during the next class period. Please consider how you will organize your team next time, make use of those experts visiting us next time, and make use of the Innovation Lab. You will be the spokesperson for your team. During class discussions, you will be responsible for communicating your team’s project effectively and concisely. During critiques (both formal and informal) expect to present your project to the critique panel and defend your team’s design choices. If you feel that another member of your team can answer a question more thoroughly, you are responsible for directing the question to him/her.
- Recorder/Photographer Team Member: Prepare any tools you plan to use to document the design/build process. Bring these tools to class next period. Be sure to take careful notes and observations along the way. Your job is extremely important as we will be redesigning our initial structures. Your notes will be instrumental in deciding future design choices. Finally, you will be responsible for documenting the engineering design process within your group and archiving your project in digital form for final submission.
Distribute
- Websites for suggested videos documenting fuel usage around the globe
- Links to Rhinoceros download for PC and Mac
- Link to general information and knowledge about Rhinoceros
- “Specific Roles For Helpful Team Members: Project-Based Learning”
Web Resources
- Video Documenting Fuel Usage Around the Globe
- “Fossil Fuels 101”: https://www.youtube.com/watch?v=zaXBVYr9Ij0
- “Humans and Energy: Crash Course World History 207”: https://www.youtube.com/watch?v=EM1IyIyr-Zc
- “300 Years of Fossil Fuels in 300 Seconds”: https://www.youtube.com/watch?v=cJ-J91SwP8w
- “Appropriate Technology Gains Ground in Developing Countries”: https://www.youtube.com/watch?v=0UrxP7cXhbA (first two minutes)
- Rhinoceros download for PC and Mac: https://www.rhino3d.com/download
- General information about Rhinoceros: http://wiki.mcneel.com/rhino/mac/home
- Optional: Work through a ‘Rhinoceros’ tutorial about rendering sketches in the digital realm at https://vimeo.com/49597954
Formative Assessments
- In class, document individual students’ responses to ‘ASK’ questions and their written and drawn work completed on sticky notes
- In class, document individual students interacting with the parabolic and non-parabolic solar oven examples
- In class, monitoring student questions posed to experts in fossil fuels and solar energy.
- Online, assess student learning through their ¾ to 1 page response in ‘Google Docs’ and through their ‘Popplet’ brainstorm.
Summative Assessments
- Student work describing and diagraming the relationship between dilation value and focal length