Lesson Write-Up For Winter Quarter 2013
Your name: Fernando Olmos
Title of Lesson: Electromagnetism: How to build your own electric car
Grade Level: 9th to 12th
Subject(s): Conceptual Physics and Intercoordinated Science
Summary:
This lesson will focus on the basic principles behind batteries and electric motors
that power electric cars. The purpose of the lesson is to understand how the principles of
electromagnetism are applied to power an electric car. A brief presentation is given to the
students consisting of a brief review of how electromagnetism work, how an electric motor
works, how a battery works, and the main features of electric cars. Then, students perform
two hands-on activities where they build a battery out of pennies and zinc washers and
they also build an electric motor out of a coil of wire, a battery, and a few magnets. Next,
students answer a worksheet based on the collected data from the hands-on activities.
Finally, a wrap-up activity is given to the students where they are given a picture of a car
with components from both gasoline and electric powered cars. Students must identify the
main components of the gasoline and the electric car. Also, they have to remember the top
5 electric cars that are now on the market.
Time Required: 2 class periods (-55 min. each). The first period will consist of a
presentation to introduce the motivation behind the activity and a hands-on activity while
the second period will consist of a second hands-on activity and filling out a worksheet and
a wrap-up activity.
Group Size: 3 to 4 people per team
Cost to implement: Approximately $100, which includes transparent plastic cups 9 oz,
jumbo sized paper clips (not serrated, but smooth), 1 250-ft spool of copper wire 22-gauge
magnet wire, 8 D-cell batteries, 100 zinc washers 1/4", 100 pennies, sand paper, table salt
non-iodized, cider vinegar, multimeter, 20 alligator clips. This is assuming the classroom
already has 10 multimeters and 30 wafer magnets.
Learning Goals:
After this lesson, students should be able to:
1. Understand how electromagnetism principles apply to electric cars
a. Learn how an electric motor works
b. Learn how a battery works
2. Learn the basic concepts on how to build an electric car
3. Learn the main features of electric cars
Level of Inquiry:
During the presentation, students were allowed to discuss in a think-pair-share
fashion features of electric cars and differences between gasoline and electric cars. With
regard to the building the battery hands-on activity, students were given the option to
experiment with different number of cells in the battery stack to find out how voltage is
affected by this. For the activity of building the electric motor, students had instructions on
how to build it; however, they had to tweak the motor components to make it work. Then,
students will be allowed to spend time to discuss and explain the different results from the
activities by answering a worksheet. Then, students will be asked to reflect, during the
wrap-up activity, on the main features and differences between electric and gasoline cars.
Introduction / Motivation:
As a mean to develop motivation in the students about the lesson, two videos
regarding electric cars are presented to the students along with a presentation that
explains the principles behind batteries and electric motors. One video was about a
documentary called “Who killed the electric car” and the other was a top 5 electric car
countdown, so students get familiarize with current electric cars.
Lesson Background Concepts for Teachers:
 An electric current produces magnetism, and a magnet can produce an electric current
 Electricity creating magnetism
 Each electron has an electric field
 When the electron moves, it also creates a magnetic field
 When electrons move through a conductor (metal or coil of wire) the conductor
becomes an electromagnet.
 Magnetism creating Electricity
 Coil of wire placed near a magnet
 Change the magnetic field by moving the magnet back and forth or spinning the
wire
 Changing magnetic field produces and electric current in the wire
 A current turns a conductor into an electromagnet
 When the electromagnet is placed near a fixed magnet, the two sets of poles repel and
attract each other
 This produces a force that makes the conductor rotate (spin) at high speed, which turns a
shaft
 First battery: voltaic pile by Alessandro Volta in 1800
 Electrons move from one metal to the other metal through a saltwater solution
 Saltwater solution is called an electrolyte
 Contains ions in solution from the dissolved salts
 Ions react with the metals making electrons.
 Metal are called electrodes
 Electrical potential difference (voltage); one positive, one negative
 Electrons move, creating an electrical current
Electric Car Features
 Runs on an electric motor
 100% pollutant emission free
 Gets power from batteries, wind, or sun
 Motor is way smaller than gasoline engine
 Quiet to drive
 Limited range (~60 to 100 miles)
 More frequent refueling
 Charging time takes hours
Procedure:
Activity Logistic
The students will be divided into groups of 3 or 4. Each group will be given a set of
instructions for the hands-on activities, as well as a data collection table. Then, students
will receive their materials and will be given time to work on the hands-on activities. The
Presentation should last 25 minutes, including time for the think-pair-share activity. The
building the battery activity should take 35 minutes. The building the electric motor
activity should take 35 minutes. The worksheet and wrap-up should take 25 minutes.
Hands-on Activities Instructions
See attached instruction booklet for details.
Materials List
Each group will need:
Do It Yourself (DIY) Activity 1: How to build a battery
Materials:
1. Small cup with water (3/4 full)
2. ½ tablespoon of vinegar
3. 1 tablespoons of salt
4. 1 straw
5. 10 pennies
6. 10 Zinc washers
7. 20 paper towel small squares
8. 1 Graph paper sheet
9. 1 Multimeter
Do It Yourself (DIY) Activity 2: How to build an electric motor
Materials:
1. 1 meter of Magnet wire 2-gauge
2. 2 paper clips
3. 1 rubber band
4. Plastic cup
5. Magnets
6. Paper Strip
7. 1 D-cell battery
To share with the entire class:
 Presentation notes, the instructions package, and the lesson worksheet and wrap-up
form.
Safety Issues:
 Do not allow students to play around with the batteries, specially shorting the
battery by connecting directly the positive and the negative side of the battery.
Lesson Closure:
A worksheet will be given to the students where they will answer questions about
the performance of the battery and the outputted voltage depending on the number of cells
in the battery stack and the performance of the electric motors. Then, students are asked if
they can identify the main components of an electric and a gasoline car in a diagram.
Finally, students will be asked if they can remember the top 5 electric cars in the market as
of 2013.
Assessment:
Pre-Activity Assessment:
The activity becomes more valuable once the topic of electromagnetism is covered.
If that topic has been studied by the students before hand, a small review of the concepts
should be introduced during the PowerPoint presentation. In addition, a think-pair-share
activity should be implemented asking students their knowledge about the difference
between gasoline and electric cars.
Activity Embedded Assessment:
Students will answer a worksheet based on the collected data from the two handson activities, which will reflect their performance in said activities. The worksheet should
assess if they can use the collected data to answer questions regarding the activities.
Post-Activity Assessment:
Finally, students will have a chance to discuss their understanding of the main
features of electric cars, and how do they work. They will be given a diagram of a car with
different components, and they will be asked to identify those. Then, students should
remember the top 5 electric cars on the market and understand their specifications. They
will do this in groups, and later share their ideas with the class.
References:
[1] http://electronics.howstuffworks.com/everyday-tech/battery.htm
Contribution: concepts explanation and diagrams
[2] http://www.howstuffworks.com/motor.htm
Contribution: concepts explanation and diagrams
[3] http://www.youtube.com/watch?v=ziWUmIUcR2k “How to Make a Simple Electric Motor”
Contribution: instructions and bill of materials
[4] http://www.ehow.com/how_5017303_make-simple-dry-cell-battery.html
Contribution: instructions and bill of materials
[5] http://www.youtube.com/watch?v=IENnSK8Q6nE
Contribution: motivational video “Who killed the electric car”
[6] http://www.youtube.com/watch?v=bYwHlQLSJaQ
Contribution: motivational video “Top 5 electric cars of 2013”
Attachments:
 PowerPoint Presentation (lesson introduction): Electromagnetism: How to build
your own Electric Car
 Students’ notes package based on the presentation
 Activity instructions booklet, data collection tables, lesson worksheet, and wrap-up
activity document
List CA Science Standards addressed:
5. Electric and magnetic phenomena are related and have many practical applications.
As a basis for understanding this concept:
a. Students know how to predict the voltage or current in simple direct current (DC)
electric circuits constructed from batteries, wires, resistors, and capacitors.
e. Students know charged particles are sources of electric fields and are subject to the
forces of the electric fields from other charges.
f. Students know magnetic materials and electric currents (moving electric charges)
are sources of magnetic fields and are subject to forces arising from the magnetic
fields of other sources.
g. Students know how to determine the direction of a magnetic field produced by a
current flowing in a straight wire or in a coil.