Teachers TryScience

Bridges

Jan 05 2012

Source: Tess

Summary Information

Keywords:

bridges, measurement, STEM, construction, budget, structure

Topic:

Measurement

Physical Science

Physics

Workplace Skills:

Raising Questions

Problem Solving

Investigation Design

Use of Data

Discussion

Teamwork

Estimated Time Required:

1-2 hours

Target Grade (Ages):

Grade 5 (Ages 10-11)

Grade 6 (Ages 11-12)

Grade 7 (Ages 12-13)

Diversity Indicators:

All students in grades 3-7.

Tab Wrapper

LESSON

Goals and Prerequisites

Goals:

By the end of the lesson, students should be able to:

Design the strongest, safest, most long lasting and economical bridge
Understand bridge design (how they are engineered to withstand weight while being durable) and that the structural strength of a material can be changed by the shape that we give it.

Prerequisites:

Students should:

Have already conducted research on their type of bridge, including knowledge of truss, suspension, cantilever, beam, arch or cable-stayed
Be able to identify forces that affect each type of bridge
Have an understanding of historical perspectives on bridges, especially Asian and Roman influences
Realize that engineers are given a budget and have an understanding of basic physics principles that create bridge differences.

Instructional Objective(s)

Students will be able to:

Classify bridges into the six major types by analyzing their structural design.
Identify forces that affect each bridge type.
Build a bridge that can hold at least 15g of weight.
Draw a bridge to scale.
Stay within a budget when building a bridge.

Instructional Resources

Background:

Bridge design has changed and improved over time.

The “clapper bridge” is one of the earliest types of bridges. This is a low bridge that is made of flat stones or logs. The “clapper bridge” is a natural bridge.

Ancient Romans refined bridge building. They used the arch design and incorporated natural cement.

Asians used a cantilever design which allowed them to build over long spans.

The Rennaissance had an effect on bridge building in that Leonardo da Vinci and Galileo developed theories about the strength of building materials. This information helped architects make strong structures from light materials such as metal.

Later bridges were built out of iron, instead of stone, brick, clay or timber. The use of metal improved bridge design. The Brooklyn Bridge is one such bridge.

The most recent achievement in bridge building is called prestressing which helps prevent concrete from cracking. Today, most bridges are made of prestressed concrete and steel.

For more detailed information about bridge design and an overview of the forces that affect bridges visit www.engineeringtufts.edu.

Materials:

Students' research information on their type of bridge.
Rubrics
Material price list
Student lab sheet
Posters of various types of bridges
Computers with internet access for clarity
Graph paper
Popsicle sticks
Pipe cleaners
Straws
Clay
Gum drops
Pieces of cardboard
Gram weights
Ruler

Procedure:

Day 1: Planning Day

Inform the students that today, they will use their knowledge about bridges to construct a bridge that meets certain specifications. Go over the rubric to identify what their finished product should encompass. Explain that they will have to adhere to a budget of $1,500. Go over the price list with the students. They will be divided into construction companies and each company will work as a team to construct their bridge. Emphasize how important it is to cooperate and contribute to the skills demanded by the task...if you do so, you will succeed.
Students should take out their notes (from a previous class) on the bridge that they will construct. Review what they already know about their bridge, e.g., what forces affect them, reasons for the design, historical perspectives.
Tell students that their next step is to have a blueprint of their model bridge. The bridge will be drawn to scale. Each member of the company will submit their blue print and the group will select the best one.
Explain that the materials for building their bridges include popsicle sticks, pipe cleaners, and straws. Clay and gumdrops will be used to connect them.
Teacher should model how to draw to scale, using a large sheet of graph paper or on a Smart Board or projector.
Tell students that 1cm on the graph paper will represent 1cm of the length of material. So that if you draw a line on the graph paper that takes up 1cm you are showing that the material used will also be 1cm. Explain that the material that is being used should also be noted on the graph paper. Remind them that the material chosen will have an effect on the bridge’s strength and that their plan should stay within the budget.
After you model, students should work on their blueprints.
Students should select the best design from their team. They will share their selected design with the rest of the class.
Teacher will ask the students why they selected that design. Explain that engineers usually design numerous times before they select the one that is most suitable.

Day 2: Building Day

Students should take out their blueprint from their project folder and place on the table. Project folders have a blueprint, price list, rubric and previous research information. Give the students some time to look over the blueprint to make sure that they still want to stick to that plan.
Each group's materials monitor will go to the designated area and collect the materials needed to construct their bridge.
Students should begin building and know that during the building process if they find that they would like to make changes to their plan, they may. They may choose to change plans because something wasn’t working or because they thought of a better idea.
Teacher will circulate the room to check for understandings and to ask higher order questions such as: What other materials could you have used today? Why? What materials would be ideal in an area that is prone to earthquakes? You may want to view Asking Good Questions for more information.

Asking Good Questions Video
When the bridges are completed, students should place gram masses on the bridge to test the strength.
Students should complete the lab sheet.
Students will share their finished products will the class.

Extensions

Students can create a PowerPoint presentation to outline their understandings. You can have them use a digital camera to show their processess in bridge construction and present this to other classes.

Students can create a brochure for a tourist of N.Y.C. The brochure will outline bridges found in the City, describing historical background, forces that affect them, and reason for design.

Assessments and Rubrics

If you are interested in learning how to make your own rubric for this or other lessons, you may be interested in watching the How to Make a Rubric video below.

How to Make a Rubric

Or, you can choose to use or customize the one created for this lesson plan below.

Building Bridges Rubric (PDF)

Credits

Tess Vannata P.S. 97Q (STEM Teacher)
Bridges Power Point (www.engineeringtufts.edu)

RESOURCES

Original Resources

Contributed Resources

Contribute a Resource

Bridge Project - Student Template

Assessment - Final Project Work

Bridges Power Point

Modified Bridge Rubric

Assessment - Rubric

Sample Student Final Presentation

Sample Student Work

Simplified Bridge Powerpoint

Lesson

Stages of Lesson/Student Work

lesson

STANDARDS/CURRICULUM

Add Standards/Curriculum

Select any filter and click on Apply to see results

Your Rating:

Your rating: None Average: 3.5 (2 votes)

Comments

Lesson Modification

I focused less on the money and the "scale" aspect of this lesson and more on the forces and types of bridges. My formative assessment was the students' notes on a reading about the different bridges (linked in lesson above), and then their sketch and plan as a group. Once shared with me (through a conference), and approved, then they built the bridge and tested it in class. Students then observed their results, and created a powerpoint (based on student project template in resources) to explain their understanding of how bridges work.

El tema es excelente y los

El tema es excelente y los materiales para construirlos son adecuados. Considero que los temas de tipos de puentes, la parte histórica o lo que se desea que los niños comprendan, estudien o conozcan, no son propios para las edades de 3 a 7 años. Es complejo que puedan comprender el tema de presupuesto y más si es en dólares. O bajaría la dificultad o lo propondría para grados mayores.

Search form

Languages