### The Power of Oreos

Contributor: Sara Leins

Type Category: Instructional Materials

Types: Lesson/Lesson Plan, Experiment/Lab Activity

Note: This resource, vetted by NSTA curators, is provided to teachers along with suggested modifications to make it more in line with the vision of the NGSS. While not considered to be “fully aligned,” the resources and expert recommendations provide teachers with concrete examples and expert guidance using the EQuIP rubric to adapted existing resources. Read more here.

#### Description

This lab activity has students making the connection between energy, the conservation of energy, work, and power. The lesson provides enough guidance to help students without directly stating what procedural steps to follow. This allows students to develop their own computational models During the lab, students will need to run or walk up stairs so that they can compute a change in gravitational potential energy, which will also be equal to the work done in raising their mass up the height of the stairs. By simply timing their ascent, the students can then calculate their power. In the end, students are to calculate how many stairs they would need to climb to burn off the calories in an Oreo cookie. The lesson comes complete with a warm up activity, notes to the instructor, an example of student work, and a wrap up activity.

Intended Audience
Educator and learner

Educational Level
High School

Language
English

Access Restrictions
Free access - The right to view and/or download material without financial, registration, or excessive advertising barriers.

##### Performance Expectation

HS-PS3-1  Create a computational model to calculate the change in the energy of one component in a system when the change in energy of the other component(s) and energy flows in and out of the system are known.

Clarification Statement:

Emphasis is on explaining the meaning of mathematical expressions used in the model.

Assessment Boundary:

Assessment is limited to basic algebraic expressions or computations; to systems of two or three components; and to thermal energy, kinetic energy, and/or the energies in gravitational, magnetic, or electric fields.

This resource is explicitly designed to build towards this performance expectation.

The lesson is designed for students to determine on their own what they need to measure so that they can calculate their change in gravitational potential energy and therefore the work that is done as they climb stairs. Because the lab instructions don’t simply tell students what to measure but instead requires them to develop their own method, the activity does allow them to create a computational model that they will use to perform their calculations. Instead of being given an equation in the lab handout, students will need to determine that the increase in their gravitational potential energy (mgh) is equal to the work done as they vertically climb the stairs. This is the computational model. The change in gravitational potential energy (mgh) is what students will use to calculate their power. One limitation of the model is that horizontal motion is ignored. A teacher may provide information about supplies and conversion factors available to the students: supplies include stopwatches, a bathroom scale, meter stick, etc.

##### Science and Engineering Practice

This resource is explicitly designed to build towards this science and engineering practice.

It may be useful for the students if the instructor drew a set of the stairs on the board (both a side view showing vertical and horizontal displacement, as well as a simplified vertical-only view) to use in a class discussion that focuses on simplifications made in the lab calculations (horizontal displacement is ignored).

##### Disciplinary Core Idea

This resource is explicitly designed to build towards this disciplinary core idea.

Students use their computational models to predict how much further they would need to climb to burn off the energy content of an Oreo cookie. These calculations show the transfer of energy from one form to another, from physical exercise to the calorie consumption to "work it off."

##### Crosscutting Concept

This resource was not designed to build towards this crosscutting concept, but can be used to build towards it using the suggestions provided below.

To fully address the cross cutting concept, the instructor will need to lead their students to examine any assumptions and approximations that were made in their procedures and calculations, and how those may have affected the predictions made from their models. One example of this, and it is pointed out in the teacher notes, is that horizontal motion is not taken into account.

#### Resource Quality

• Alignment to the Dimensions of the NGSS: The lesson blends the practice, disciplinary core ideas, and cross cutting concept to ensure three dimensional learning for students. Students need to use definitions of energy along with the conservation of energy to create mathematical models that will allow them to determine the energy they expend when climbing stairs. To fully address the cross cutting concept of system models, the instructor will need to have their students examine any assumptions or approximations they made in developing their computational models and how those assumptions and approximations may have affected their predictions. To provide some motivation for doing the activity and wanting to utilize energy concepts, an instructor could start the lesson by asking students how much energy they can get from an Oreo cookie.
• Instructional Supports: This lesson blends the three dimensions while providing students with a first hand experience to engage in the practice of creating a computational model. It builds on students’ prior knowledge of energy as it uses that to guide students to go beyond simple definitions of energy and apply that to create a model of the conservation of energy. A shortcoming is that the lesson could provide more support for struggling students in the way of a vocabulary list and more direct guidance in how to create the computational model. Another shortcoming of the activity is that it doesn’t provide students the opportunity to express, clarify, justify, interpret, and represent their ideas and to respond to peer and teacher feedback orally and/or in written form as appropriate. Building communication into the lesson would make it stronger. In addition, there isn’t scaffolding and it doesn’t explicitly address how prior knowledge will be used.
• Monitoring Student Progress: Monitoring student progress is limited to formative assessment in this lesson, and needs to be strengthened by a rubric to evaluate the students' performance of 3-dimensional learning in the lab write-up. There isn’t a rubric for the teacher or students to use as a guide. However, the lesson does at least contain a sample lab write up for the teacher to use as an example. The instructor could use this example as a guide to help struggling students, or at least as a guide when creating their own rubric. There is a short class discussion before the lab activity, but it focuses mainly on vocabulary. However, this serves as a formative assessment which quickly lets the instructor know how much support the students will need to not only define energy, the conservation of energy, and power, but also to create models involving energy and energy conservation. In addition, the lesson contains a few practice problems for students to work on before they begin on the lab. It is recommended that the instructor go over these after the students have had a few minutes to work on them without guidance from the instructor.
• Quality of Technological Interactivity: There are PDF and PowerPoint files embedded in the lesson, but they will open on all platforms.

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