Italy High School

Introduction

Have you ever looked at a bridge spanning a deep chasm or a massive expanse of water and wondered…How did they do that?  Understanding the engineering and physics involved in bridge building will help you build your own bridge.

Task

You will design and build the lightest bridge capable of supporting a given load for a given span of time.  The bridge will be made of regular wooden toothpicks approximately 7 cm long.  You will also provide a sketch and a journal of what you are doing.  All bridges will compete in our class contest.

Process

1. To understand more about types of bridges, go to Build a Bridge and read about each of these 4 types of bridges by clicking on each type of bridge as you scroll down. 

2. After you read about each type of bridge, then go to Step 3 and play the game by trying to match the correct type of bridge to the location.

3. Check out 6 Basic Bridge Types here.

4. Try Bridge Basics for more bridge designs.

5. Now find out How Bridges Work here. 

6. Also look in the reference section of the library in encyclopedias for information on different types of propellers and Newton’s Laws or the online encyclopedias at the Italy High School Library web site.

7. Now use the Big6 research method or the Scientific Method to help in this project.

8. Keep a journal as you progress through this project.

9. Decide what type of bridge design you will use.

10. Sketch your bridge design with a front and side view with labels and sizes, and then turn it in.

11. Now build your bridge following these rules:

--As light as possible

--Spans a gap of 40 cm +/-.5cm

--Can support 3 lbs. for 10 seconds

--No taller than 20 cm

--Does not touch the base of the support structure

--Can only touch the top of the support structure

--No part of the bridge can extend 10 cm below support structure

--Must have a roadway of 3 cm or more

--Only use wooden toothpicks and Elmer’s glue

--Cannot be painted or coated

12. Include in your journal a final analysis/self evaluation on how well you think you did on this project.  Include:

--What did I do that was really well done?

--How could I improve next time?

--What went wrong and what you would do differently?  (If bridge does not work)

--What have you learned?

--What sources were the most useful?

--What sources did I need to do a better job that I didn’t have this time?

Evaluation

You will receive 1 test grade for this project in the following breakdown of 100 points:

--Sketch (10)—must have a side view and a front view with labels and sizes

--Bridge design (55)—neat design and good construction (10), complete on time following the rules (30), strength (10), light weight (5)

--Journal (20)—turn in on time

--Final analysis/self evaluation (10)—include all points outlined above

--Biggest load to weight ratio (5)

Conclusion

At the end of this project you will become an expert on the physics involved in bridge design and engineering.  Good luck in the contest!

Credits

Clip art courtesy of Cool Clips  

revised 17 February 2006