Skip to Content

Sorting Trash with Static Electricity


Author(s)

Bruce C. Palmquist
Department of Physics / Department of Science Education
Central Washington University
palmquis@cwu.edu

Abstract

Recycling plastic is an effective way to reduce waste in landfills. However, in order to effectively reuse recycled plastic, different types of plastics must be separated from one another. This is a time intensive task. Engineers in Japan have tested a way to separate plastics using static electricity. In this interrupted case, students will design a method to separate plastics using static electricity, make hypotheses based on what the Japanese engineers did, and analyze their actual data with a focus on bar graphs. The case can be used as a course transition from electric charge to electric fields. Students should have prior knowledge about the triboelectric series and Coulomb's Law; they should also be familiar with the basic kinematic equations for objects moving with constant acceleration. Although originally developed for an introductory calculus-based physics class, calculus is not required, and so the case can easily be used in an algebra-based college physics class or even a high school physics class that covers static electricity concepts.


Objectives

  • Use the triboelectric series to predict the relative strength of a charge.
  • Apply the definition of electric field and basic kinematic equations to determine the relationship between charge and displacement.
  • Design an experiment, specifically describing the basic procedure, number of trials, equipment needed, and method of analysis.
  • Given an experimental set-up, sketch a graph of a hypothetical outcome.
  • Given a description of the axes of a graph, develop and defend a conclusion based on the graph.

Keywords

Static electricity; electricity; electric field; charge; triboelectric; recycling; plastics; experimental design

Topical Areas

N/A

Educational Level

High school, Undergraduate lower division

Format

PDF

Type / Methods

Interrupted

Language

English

Subject Headings

Physics  |   Electrical Engineering  |   Engineering (General)  |  


Date Posted

3/20/2014

Teaching Notes

Case teaching notes are password-protected and access to them is limited to paid subscribed instructors. To become a paid subscriber, begin the process by registering.

Teaching notes are intended to help teachers select and adopt a case. They typically include a summary of the case, teaching objectives, information about the intended audience, details about how the case may be taught, and a list of references and resources.

Answer Key

Answer keys for the cases in our collection are password-protected and access to them is limited to paid subscribed instructors. To become a paid subscriber, begin the process by registering.

Comments