2nd Quarter Bridge Project

Purpose: to study the structural properties of bridges

to build a bridge and test is support capacity

to learn about science references and resources

Materials: balsa wood sticks (36 x 3/32 x 3/32 inches)

Purchase from Michael’s in Sterling. Ask for the type that Dr. Krovvidy

Ordered.

Elmer’s wood glue

Procedure:build a bridge that will span 30 (L) cm x 8 (H) cm x 8 (W) cm or less

bridge mass cannot exceed 20 grams

complete a force diagram showing the structural support

write a report about your style of bridge

Calculation: your bridge must be able to support 1000 times its mass

Report:a typewritten report on bridges with photographs (2 pages)

do a brief introduction explaining the different types of bridges

include history and physics of bridges, emphasis on the type

you chose

identify the structural components of your bridge

write on your team’s experience and procedure used

use reference books, science or engineering texts; refer to

internet web sites; document all sources of information

Grading:3 to 4 students on each project team

all participants get the same grade

each student must participate equally

grade standard: see reverse

Due Date:

Final Results:

bridge name:______Team: ______

mass of bridge: ______g ______

support mass: ______g ______

support ratio: ______

Grading Rubric

Summative: Bridge Support structure / Design: 30 + 30 = 60 points

Formative: Report / Force Diagram : 40 points

Do NOT make a Beam Bridge EVER!!

Bridge Project Rubric
Looking For… / Way! /

Part Way

/

No Way

/

Scoring

Report – Spelling and punctuation
Paragraph form / Well written with proper sentence and grammatical form done in the authors’ own / Partly copied from website or text. Only partially addresses the topics / Copied word for word from text or web site
(BIG NO-NO!!!)Poorly written with sloppy presentation / Spelling,
Grammar,
Punctuation
/5
Quality of Report
/10
Report – Documentation / Bibliography with wide selection of references from books, periodical and internet sites / Partial listing of one or two references / Bibliography missing / Documentation
/5
Force Diagram – your bridge diagram / Accurate drawing of your bridge – not every stick needs to be shown / Drawing is missing one or more critical structures / Drawing does not represent the bridge at all / Bridge Diagram
/10
Force Diagram – Vector lines / Force vectors lines with arrows accurately display how the bridge supports the road surface / Some force vector lines are accurate, but important ones are missing / Force lines are missing or do not show that structure at all / Vector Force Diagram
/10
Bridge structure – Mass compared to support amount / Calculate the mass to support ratio and it exceeds 100 : 1 by a considerable margin / Calculate the mass to support ratio and it is between 50 and 100 : 1 / Calculate the mass to support ratio and it is less than 50 : 1 / Ratio > 50:1 15 pts
Ratio > 75:1 18 pts
Ratio > 100:1 20 pts
Ratio > 500:1 25 pts
Ratio > 600:1 26 pts
Ratio > 700:1 27 pts
Ratio > 800:1 28 pts
Ratio > 900:1 29 pts
Ratio > 1000:1 30 pts
Bridge structure – Design and creativity, workmanship / Bridge uses or modifies one of the standard structural types with creativity and ingenuity. Neat and without glue sticking out / Bridge copies a trivial design type with little imagination
Somewhat neat, some glue showing / Bridge design shows very little thought or design creativity
Messy, irregular, with splinters & glue showing / Creativity/Workmanship
/30