This lesson address the Crosscutting Concept Energy and Motion, specifically the Middle School focus, "Energy may take different forms (e.g. energy in fields, thermal energy, energy of motion) and Science and Engineering Practices 3 and 7.
SP3 Planning and Carrying Out Investigations
SP7 Engaging in Argument from Evidence
This lesson sets out to challenge students to build a roller coaster that has at least one hill and one loop. Their goal will be to gently roll a marble into a cup at the end of the "ride."
Students are asked to measure the height of each hill and loop during each attempt to construct their coaster. They should record any observations in their notebook.
The added challenge of getting the marble to gently roll into the cup will spark collaboration.
Students will be using Predict, Explain, Observe, Explain (P.E.O.E.) to elicit their preconceptions and post-conceptions.
Give students this KLEWS chart and have them fill in column 1. They should attempt to answer the question at the top of the chart. Later, students will revisit this chart as they learn about energy and record questions that they have in the 'Wondering' column.
Before we begin creating and testing roller coaster designs, I ask students to create a data table that collects all the required information (SP3). Most tables include: trial #, height of hill, height of loop, and observations for test.
Groups of 3-4 students then gather their materials and move to their designated area. I like to assign students to go along the perimeter of the room, so that marbles are easier to locate if they take an errant turn.
It is a good idea to use roles, such as marble roller, marble fetcher and coaster constructors. Students can change roles throughout class so that everyone gets an opportunity to perform different aspects of the activity.
Designing solutions in engineering starts with an idea that is usually drawn out and then implemented. I want to encourage my students to test specific ideas, as opposed to simply messing around with foam and marbles (SP3). If they have a plan, than they are more likely to take their time while measuring the height of each part of the coaster, recording the results of the test and learning from their evidence. Therefore, I require each group to have a sketch of what they want to do prior to constructing and building their design.
After students have a sketch of their design, they fill in the Predict and Explain portions on the left hand side of the P.E.O.E. that they create in their notebooks. Since this is the first time that students would be using P.E.O.E., I modeled the strategy for my students.
Following a procedure is an important skill, but it's important to note that my procedures are not directions for specific tasks that I want students to perform. In other words, I am not giving them predetermined tests that have neat, predictable outcomes--that's too cookie cutter. However, that doesn't mean that I am not providing the necessary structure and then get out of the students way. It's important that we pick appropriate strategies in our classes, so that the learning is both student-centric and meaningful.
I write the following steps on the board as the procedure for the following lesson:
1) Draw a sketch in your data table about what your coaster will look like.
2) Fill in the Predict and Observe portion of the P.E.O.E.
3) Build, measure heights of all hills and loop; record in your data table.
4) Fill in the Observe and Explain portion of P.E.O.E after you test your coaster.
Students are given the freedom to create whatever coaster design that they choose, they only have to follow the steps above.
Note: The loop must touch the ground
Once they have one design, students can begin testing. After the first test, they have gained a hands-on experience about what it is going to take to successfully drop the marble into the cup.
This drives their collaboration, as they reflect on the results of the first test and design a new solution they confer with each other. This is an important moment, and you should watch to make sure that the takeaway from the experience and resulting ideas for improvements is considered from each member of the team. Students make modifications to their designs, and repeat the process, making sure to measure the height of each hill and loop, until they successfully drop the marble into the cup.
Once students have tested their designs, they should work together to fill in the Observe section of the P.E.O.E..
Note: They don't have to agree about why it is happening. They should reflect on their original predictions and explanations and reflect. (SP7 Respectfully provide and receive critiques about one’s explanations, procedures, models, and questions by citing relevant evidence and posing and responding to questions that elicit pertinent elaboration and detail.)
If certain groups are successful in the first few minutes of class, it is important that they can replicate the results, so have them show you again. Also, it is equally critical to have them reflect on their experiences. Have then write a journal entry in their notebook about what they learned from the experience. (If you don't have a moment to watch students demonstrate their results, have the work on their reflection first, with the understanding that it may have to be revised after they conduct their demonstration for you.)
I am attempting to get students to develop an understanding of gravitational potential and kinetic energy without "teaching" them.
The purpose of this lesson is for students to realize that the initial height of the first hill determines the size of the rest of the coaster's parts (i.e. loops, etc.). Regardless of whether students are successful at getting the marble in the cup, they will have an entire data table of entries that they can use during their reflection.
Homework: Students should write a 7-10 sentence reflection that summarizes what they learned about roller coasters and energy. In addition, they should write any questions that they have about energy in the Wondering column of their KLEWS chart.