The Why Behind Teaching This:
Unit 3 addresses standards related to the transfer of energy and matter between organisms in an ecosystem. The unit begins with identifying what solar energy is and what two forms of energy solar energy provides to life on Earth. This is an important foundation for understanding standard 5-PS3-1: Use models to describe that energy in animals' food (used for body repair, growth, motion, and to maintain body warmth) was once energy from the sun. We build on this knowledge throughout the unit in other lessons related to photosynthesis and how animals use the energy they get from food. In this unit students will also be conducting experiments to gather evidence to support their belief that plants get the materials they need for growth from either water, air, or the soil. This is covered in standard 5-LS1-1: Support an argument that plants fet the materials they need for growth chiefly from air and water. Students will be creating food chains and food webs to describe the movement of matter among organisms in an ecosystem. This is covered in standard 5-LS2-1: Develop a model to describe the movement of matter among plants, animals, decomposers, and the environment.
I combined these three standards all into unit 3 because teaching them together allows students to see how they are all connected. The energy that plants get from the sun is stored in their parts until animals consume them. Plants cannot absorb this energy and reproduce without other materials from the environment such as carbon dioxide from the air, and water and nutrients from the soil. The animals that consume the plants use part of the energy for growth, reproduction, etc. but they also store some of the energy. That energy is then passed on to other animals once eaten. All of the energy that is available in an ecosystem can ultimately be traced back to the sun. Teaching all of these standards together, instead of in isolation of each other, makes that connection easier to see.
This specific lesson is linked to standard 5-PS3-1: Use models to describe that energy in animals' food (used for body repair, growth, motion, and to maintain body warmth) was once energy from the sun. This lesson is laying the foundational knowledge that solar energy can be transformed into other forms of energy, in this case electric energy which is then used for movement (kinetic energy). Once students have this background knowledge, we will begin applying it to plants ans animals.
Students are working through the steps of the engineering design process in this lesson which is covering standard 3-5-ETS1-1: Define a simple design problem reflecting a need or want that includes specified criteria for success and constraints on materials, time, or cost. They were taught the design process in an earlier lesson using the Engineering Design Process Template.
The goal of this lesson is for students to build a car that converts energy from the sun into electric energy that powers the cars motion, and to draw and label a model explaining the transfer of energy.
Students will demonstrate a clear understanding of the goal by submitting their labeled model for grading. All descriptions labeled must be accurate and show they truly understand how energy is being transferred through the system.
Preparing for Lesson:
Prior to this lesson, you will need to order solar panels for the cars you plan to build. I ordered kits from Junior Solar Sprint.
Students will be building their cars and testing them. For building, you will need a variety of items and tools available for them to use. Some example might be:
For testing the cars you will need:
A copy of the Engineering Design Process - Solar Powered Car Exit Ticket for each student
Building the Solar Powered Cars:
The first 30 minutes of today's lesson groups work on building their cars that they designed in the first part of this lesson. Any groups that did not complete their planning sheet and get it approved will need to take a few minutes to complete that and get it approved prior to beginning to build. Each group has the solar powered panel set up for their car, they just need to construct the rest of their car and attach the wheels.
Testing the Cars:
Groups will not be able to test their cars and make improvements until we go outside. Testing and making adjustments to the design is part of the design process and is important to teach the students. They spend the next 30 minutes building their cars inside and then we move outside. When we go outside to test, all groups will make sure their cars are running. If they are not working properly they spend time making adjustments to get it to work.
None of the cars worked the first time as you can see in the video of group testing car that won't work. It was the responsibility of each group to figure out what the failure point is and make improvements to get it to work. You can see in the video of group improving their car after a failed test that they work together to trouble shoot and make changes. After they make the changes they think will get it to work, they test again. Still none of the cars worked. Groups tested and make adjustments several times. Once groups started to get cars working, they were so excited. You can see in the video of group getting their car to work that once they get moving, they keep on going until they run into a shady spot.
Exit Ticket To Check for Understanding:
Once inside, I record the best time for each group on the overhead so that everyone can see. I then pass out a Engineering Design Process - Solar Powered Car Exit Ticket and a sticky note to each student. I explain the directions to the students. I explain that what I want to see on the exit ticket is a picture of what source of energy was used for this activity. How that energy was absorbed by the car and then how it was transformed into energy that was useful to the car to make movement. I want descriptions to be detailed so that it is clear they understand. We went over this process several times as we were testing the cars so they should know what I am looking for. I tell them to keep the sticky note until I give them further directions with that.
Extending the Activity Through an Experiment:
After exit tickets are turned in, I ask students how the position of the sun in the sky might affect the speed of the solar powered car? I explain that a group of students tested this by conducting an experiment. I have my students make a hypothesis on the sticky note that was provided with the exit ticket about what they believe the outcome will be. Then, I share the experiment and results with the class by going to the online Dragonfly TV article. I encourage students to test this at home and find out if their data supports the original findings.