http://www.stevecoxon.com/toothpick%...on%20coxon.doc
Toothpick Bridge Explosion
Edited by Sarah Smith
Originally by Steve Coxon, MAEd
Introduction:
Using only toothpicks and glue, you will construct the strongest bridge you possibly can. Then we will hold a competition
to see which bridge is the weakest and which bridge is the strongest!!
Subject
High school honors physics class (approx. 11th grade)
Topic:
Researching bridge design then design and build a bridge from toothpicks to hold the most weight
Objectives:
Students will use the internet safely and ethically to research 5 famous bridges and their design.
Students will understand which geometric shapes are the strongest.
Several students will effectively learn and use excel software to budget and track their funding for the build project
Students will work collaboratively in groups of four to develop a blueprint design then present their design as a group to
the class
Each group will delegate a specific role to each individual team member for the building process.
Procedures:
1. Divide the class into groups of four
2. Give 5 minutes for them do assign roles (account manager, research manager, design artist, supply manager)
3. Give 10 minutes for them to review contest rules, list of materials, price sheet
4. Allow the “research manager” to sign into a computer and then for the remainder of the period they may research and
write a brief description of 5 famous bridges and their design type (ie. Suspension) The research manager will type up a
very brief reports and print it out for later reference
5. Day 2: Separate into groups and the “design artist” will begin drawing the design using an actual toothpick for scale
6. Each group stands and shows their design to the class, discussing what elements they are focusing on
7. The “account manager” will discuss with the group a preliminary budget and then put this into an excel document.
*Each group has only $250,000
8. The supply manager will then purchase materials from the teacher and maintain them personally (responsible for and
losses)
9. Day 3: Build off!!!
10. Day 4: Weight competition. Using a pencil and string, hang the bucket. Slowly add 1 battery at a time until it breaks.
Materials needed per team (4 students):
Pencils and large white sheets of paper
Centimeter ruler
Dixie cups (for distributing glue in small portions)
Wood glue
Wax paper
250 round toothpicks
Small zippered bag (for securing toothpicks)
Bag of clothes pins
Materials needed per competition/ceremony:
Matchbox car and boat (optional)
Bucket, weights (40 D-cell batteries work well), and string to hold the bucket.
Basic Rules:
1. No materials may be used as part of the bridge except the toothpicks and wood glue provided.
2. Toothpicks may not be broken. Imperfect toothpicks may be traded in for new ones.
3. The bridge may not touch the ground at any point outside the “Leg” squares.
4. The matchbox car must fit inside the bridge (it does not actually need to drive across), and the boat must be able to slide
underneath the center. OR The bridge legs must be at least 3cm wide, and the bottom of the bridge arch must stand at
least 5cm off the ground.
5. The bridge must be free standing or it will be broken on its side.
6. All bridges will be broken by being set across two tables 15cm apart and having a string tied around the middle that is
connected to a bucket which will be filled slowly with weights. The bridge that is able to hold the most weight before
breaking wins the contest.
Price List:
Give each team a $300,000 budget.
$1,000 per toothpick
$50.000 for wax paper (land)
$5,000 per ½” of glue
$10,000 for your consultation
$2,000 per clothespin
Evaluation:
Ask the students questions about bridge types and vocabulary (ie. Trusses) to see what students already know
Following the printing of the brief reports, check to see what each group has learned from their research
If each group has build a standing bridge that models and actual type of bridge and holds any weigh at all they have
complete the task
Extension ideas:
1. Bring in a civil engineer to speak to the students about bridge building.
2. Make first bridges, hold contest, study bridge design, do a second bridge contest.
3. Cut the number of available materials in half
Other Resources:
http://www.matsuo-bridge.co.jp/english/bridges/index.shtm
http://42explore.com/bridge.htm
http://www.pbs.org/wgbh/nova/bridge/
http://www.exploratorium.edu/science_explorer/card_bridge.html
http://www.sciencebuddies.org/science-fair-projects/project_ideas/home_CE.shtml
ISTE Standards:
Digital Citizenship
Communication & Collaboration
Technology Operations and Concepts