Empowering Minds through Powered Cars

Carole K. Lee
Marilyn Shea

Abstract

This vignette describes how a teacher educator uses a car building STEM activity as a tool to help pre-service elementary teachers develop their creativity, communications, problem solving, and achieve deeper understanding of the science concepts of power and energy through a three-stage process. 

      The 100-minute lesson, described below, was for pre-service elementary teachers in Science Education K-8, a science methods class, which emphasizes constructivist and inquiry-based learning and teaching of science. The students were preservice education majors. Previous to the introduction of the activity, course participants were introduced to basic concepts in physics and discussed concepts and applications that would be appropriate for elementary school children.

       The purpose of the activity within the college classroom was two-fold; 1) to model a scaffolded lesson where the students were independent but guided by questions and observations and 2) to reflect on how the same techniques could be adapted to the elementary school curriculum with an emphasis on scientific testing and an understanding of the scientific principles involved. As Darling-Hammond and Oakes (2019) emphasize, modeling deeper learning practices in education content courses is essential so future teachers “… explore thinking and problem solving in the discipline and acquire a much deeper understanding of how to represent the content…” (p.75).

Science is indeed hands-on, but the hands must be guided by an informed mind.

       I, being the science educator and the first author of this article, employed a three-stage process to include the cognitive challenges of explore, experiment, and evaluate in this STEM activity. No written handouts are provided for the students.The flow of the lesson depends on the responses of the students and questions that I improvised on the spot. The science concepts of force, motion, and energy had been covered in previous lessons. 

Stage 1 – Exploration and Divergence

       I chose to use a STEM activity of building a toy car to illustrate the science concepts of energy because building a car is interesting and related to the daily lives of students. The Framework for K-12 Science Education (National Research Council, 2012) states that teachers should provide students with learning experiences that are related with the world and model how scientists investigate and find answers to questions. 

       When I walked in the classroom, I said to the pre-service elementary teachers:

Today, we are going to build a car . . . one that can run by itself. How are you going to do it? You will work in groups of three or four, think about the problem, and sketch out your plan.” 

             I intentionally provided the course participants with a brief introduction which was to arouse their interests, to get them engaged, and to think independently. At the same time, I brought a variety of toy cars to play with. This was to encourage divergent thinking. The course’s students got excited and asked many questions such as “What materials are provided?” “How big is the car?” “How far does the car have to run?” “Can we use batteries?”

       To start off, the students searched the internet to find further examples of powered cars. Exclamations and excitement filled the classroom when they saw some amazing demonstrations on YouTube videos.This initial stage was planned for the students to collaborate, converse among themselves, and to help one another to collect information to widen the range of possibilities. As they discussed, I paused at each table to ask questions to help them express their hypotheses and to encourage them to think critically, in order to test their ideas. “What shape would be the most aerodynamic?” is an example of scaffolding questions I posed.

Stage 2 – Creation, Experimentation, and Explanation

       One of the model cars provided could run by itself when pulled back. The students were curious about its mechanism and asked, “What makes the car run?” Some said, “The car has power” while others said, “It has energy.” At this moment, I noticed the students were confused with the terms power and energy. I grabbed the teachable moment and helped the students discuss the relationship between power and energy. I asked, “Which vehicle do you think has greater power, a cargo truck or a passenger car?” Almost all students said it was the cargo truck.

       The next question was, “Why do you think a cargo truck has more power?” They thought for a while and said a cargo truck could carry a heavy load. Some said a cargo truck had more power because it could go faster. The discussion went on for about 20 minutes. The students discussed the measure of power based on the principle that energy is defined as the ability to do work and power is the rate at which the energy is generated.

      They were applying principles learned in previous lessons. I allow students to engage in the process of exploring questions rather than the process of “finding the correct answer.” Some students would reach for their phones to “look it up.” I discouraged this; it is better to get them to test their own hypotheses.Your students will be on their way to success if they talk about testing things like friction and efficiency.

       Focusing on the pulled-back car, I asked, “Where does the energy of the car come from?” One said, “The spring inside.” That question led to “How does the spring work?” and “What do we call this kind of energy?” Guided questions help students to construct their experiments. The students were able to state that the torsion of the spring provided the energy and this kind of energy is called potential energy. Some of them recalled they had made a spool car which was run by torsional energy when they were in elementary school.

      The pre-service elementary teachers created a variety of cars – spool cars, balloon cars, and chemical (vinegar mixed with baking soda) cars. When watching the YouTube videos, the students thought building a car was straightforward and simple, but when they did it, it was harder than they expected. They had many questions:

Why doesn’t our car run? What goes wrong?
How much of the chemical mixture should we use? 
How can we make the car go faster?
How can the car go a longer distance?

       I reinforced students’ curiosity by congratulating them on good questions and suggesting that they should devise tests to determine the answers to their questions. Some students wanted to make their cars go faster. That provided the perfect opportunity for them to reflect on the process to test different configurations and different variables. The central question “What propels your car?” acts as a catalyst for students to examine the factors that influence the movement. Wind energy propels a balloon car and baking powder interacting with vinegar propels a chemical car.

       Doing a series of experiments to improve the design of the chemical car, the pre-service elementary teachers found that when more baking powder or more vinegar was added, more bubbles (carbon dioxide) were formed and more energy was produced. The balloon car groups realized they needed to blow a bigger balloon. Some students making the balloon car had the “aha” moment. They noticed the application of Newton’s third law – action and reaction are equal and opposite – when they saw the air inside the balloon was escaping in one direction while the car was moving in the opposite direction.

Stage 3 – Evaluation

      Evaluation occurs on two levels. The students focused on the outcomes of the experiments, whereas I focused on and reinforced the exploration of different options such as the design and the propulsion of the car and the improvements made after every trial. I emphasized that the success of the task is not based on the winning speed but on the process of creation, testing, and explanation. A student who can say why a car didn’t work has learned more than one who cannot explain why it did work. 

      At the end of the unit, a class discussion was conducted with the following questions:

What worked well?
What could be done to improve the experiments?
How do the activities reinforce what you have learned about energy?
How would you teach the topic energy to elementary students?

Reflection

       Though this lesson was in a college science methods class, it can be used in elementary or middle level classrooms. Though it was about building a car, you could do similar lessons with kites, windmills, boats, and more – use your imagination. The point is the development of a deeper understanding of power and energy by allowing the students to have a trial-and-error experience of doing and learning by themselves. Students learn best by testing, trying, and maybe by failing at times. It is through the failures that students learn to hypothesize and test

       Vygotsky’s principles of scaffolding and guided instruction underlie the modeling I do in class that helps pre-service elementary teachers learn to use the dialectic method of questions and answers in their own future classrooms (Castagno-Dysart, Matera, & Traver, 2019). To promote students’ divergent thinking, I deliberately involve students in designing their activities or experiments instead of providing them with a set manual. In the future, I will ask students to design an experiment to test one of the variables in their car project. A simple half-page written response will get them thinking more formally. All these pedagogical strategies help students to have a deeper understanding of the science concepts and not just the activities alone.

      Moscovici and Nelson (1998) used the word “activitymania” to describe the use of many disconnected activities to teach science in the classroom.This practice emphasizes the task and task completion rather than the understanding of science. Though students have completed tasks, they have a superficial grasp of scientific principles. Science is indeed hands-on, but the hands must be guided by an informed mind. When my students engage in science activities my goal is that they know not only the “the what” (mechanism) but “the why” (underlying reasons). I want my students – and their future students – to be able to think, assimilate, and apply what they have learned to multiple contexts.

     I want pre-service teachers to understand that though doing science activities with their students is essential, the ultimate goal is for their students to expand their science knowledge and to learn general principles through the activities.

References

Castagno-Dysart, D., Matera, B., & Traver, J. (2019). The importance of instructional scaffolding. 
Teacher, April issue. https://www.teachermagazine.com/au_en/articles/the-importance-of-
instructional-scaffolding

Darling-Hammond, L. & Oakes, J. (2019). Preparing teachers for deeper learning. Harvard Education
Press.

Moscovici, H., & Nelson, T. H. (1998). Shifting from activitymania to inquiry. Science and Children, 
January issue, 14-17, 40.

National Research Council (2012). A framework for k-12 science education: Practices, crosscutting
concepts, and core ideas. Washington, DC: National Academies press. 

Carole K. Lee, PhD is Associate Professor of Elementary Education at the University of Maine at Farmington. Her areas of expertise are professional development of science teachers, inquiry-based science teaching and curriculum development.
Email: carole.lee@maine.edu

Marilyn Shea is Professor of Psychology at the University of Maine at Farmington. She received her PhD degree in Psychology from the University of Kansas. She specializes in learning theory, creativity, and social psychology. She also teaches child development courses for future teachers.