3 (1 reviews)
5 teaching my daughter
Reviewed by: Patricia Mendenhall on 10/18/2018 3:51:50 PM
very helpful information
This is a lab activity involving transformations between the gravitational potential energy, elastic potential energy, and kinetic energy of a system. An air track with a glider and a photo gate timer are needed to perform the lab. The lab is divided into three separate but related parts. The first part involves using a spring to launch the glider horizontally, measuring the velocity of the glider, and then relating elastic potential energy to kinetic energy. The second activity involves adjusting the air track so that when the glider is launched, it goes up an incline. This set up allows students to relate elastic potential energy to gravitational potential energy. The third and final activity ties elastic potential, gravitational, and kinetic energy together. Using the knowledge they acquired from the first two activities, the students need to use Conservation of Energy to predict the velocity of the glider as it is launched up the incline and then compare their prediction to the experimental value.
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.
Comments about Including the Performance Expectation This activity gives students the opportunity to use the models of elastic potential, gravitational potential, and kinetic energy as well the law of Conservation of Energy. However, none of the three activities require students to develop their own models. To fully meet the Performance Expectations, this lab needs to require the students to develop their own models. Because this activity does not provide the relevant background knowledge, the instructor will need to preface this lab with a lesson on elastic and gravitation potential energies and the law of Conservation of Energy so that the students can gain a deeper understanding about why those energies are equal in activity two.
This resource is explicitly designed to build towards this science and engineering practice.
Comments about Including the Science and Engineering Practice In the third activity, students use mathematical models to represent various forms of energy and to make predictions about what will happen to the system To fully align with the practice, the students should develop the model and explain why, beyond sources of error, there is a difference between the speed of the glider they predicted and what they measured. The concept of some friction should be taught before performing this experiment so that the students can measure the friction present in the lab and use the work done by friction to help account for the difference in theoretical and experimental speeds.
This resource is explicitly designed to build towards this disciplinary core idea.
Comments about Including the Disciplinary Core Idea The activity focuses on how the elastic potential energy of the spring was transferred to the glider where it manifested itself as either kinetic energy or gravitational potential energy. Since the glider is sliding on an air track, friction is minimized, thereby allowing measurements that closely match theory and allowing students to appreciate the validity of the Law of Conservation of Energy.
This resource is explicitly designed to build towards this crosscutting concept.
Comments about Including the Crosscutting Concept The Law of Conservation of Energy is at the root of this activity. Students are required to assume that energy is conserved and that there is no friction to determine the spring constant of a launcher and to predict the velocity of a glider on an air track. The students are to compute the percent error between their theoretical velocity calculations and their empirical data. To better address the idea of conservation of energy Crosscutting Concept, have students explain why measurement error isn’t the only explanation for the difference between the measured velocity and the calculated velocity.