Grade Level: 5th Total Time Required:
4 – 35-45 minute sessions
Prepared by : Brittnee Garrett and Rachel Kennedy
Source:
Lesson Objectives: (List any 3 that directly apply to the lesson)
Students will be able to:
 Define and use the words “load” and “span” when discussing the purpose and construction of bridges.

Communicate their initial design plans and ideas for improvement effectively.

Explain how limitations in cost and materials might affect the construction and production of prototypes.
Indiana Science Standards:
Content specific:
5.4.2 Investigate the purpose of prototypes and models when designing a solution to a problem and how limitations in cost and design features might affect their construction.
The Design Process

Identify a need or problem to be solved

Document the design plan during the design process
Mathematics Connections: (Identify 2 or 3 connections or standards that apply)
5.NF.5 Interpret multiplication as scaling (resizing). This standard will be addressed during the conclusion section of this lesson. Students will scale the size of their bridge to the true size of the bridge. We will give them the scale, and students must calculate the actual size of the bridge. Students will convert the true size of the bridge to an appropriate unit.
Students will practice multiplication, using money, to determine the cost and efficiency of the bridge. Students will calculate the cost of their bridge based on the cost for the materials. At the end of the lesson, the students will compare the cost of their bridge to its ability to meet the requirements. We will have a class discussion about the weight each bridge could hold in comparison to its cost. This discussion will include the importance of being efficient with money in the real world.
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Science Concepts / Vocabulary: (List and define relevant science/engineering/mathematical terms will use or need to know)
Term
Load
Span
Defined by a scientist or engineer
A mass or weight supported by something; the forces to which a structure is subjected to
An extent, stretch, reach, or spread between two limits; the spread or extent between abutments or supports, as of a bridge
Model A structural design; usually a miniature representation of something
*Definitions from: Merriam-webster.com
Defined by a 5 th or 6 th grade student
The amount of stuff that something can hold or carry
The distance between two objects or points
A smaller version of an object; someone who displays clothes
During this lesson, we will discuss the science concepts of load, span, and model. We will introduce load as the amount of weight that is supported by a structure, which is a bridge in this case. The load of a bridge is important to consider because it affects the amount of weight that can be on it at one time. If the load on a bridge is too much, components of the bridge will break, causing the collapse of the bridge. Additionally, span is the distance between two limits. In relation to bridges, the span is the distance between the two landforms that the bridge is connecting. Span is important in determining the size of the bridge, especially the length. Span and load have an important relationship. As the span of the bridge increase, the potential amount of weight that it can hold also increase. Models are scaled representations of an object that are used to access something that is otherwise inaccessible. In relation to bridges, models are scaled down representations that can aid in the design process. Multiple models can be made at a relatively low cost. When designing bridges, it is important to consider the cost of materials as well as to be resourceful when using materials. This will allow for a bridge to be built that meets the requirements but also uses as few resources as possible.
List the quantities of all materials and equipment needed:
Tools
Electronic Scale (3)
Meter Stick (6)
Tables (2)
Weights (10 bags of rice)
Stop watch
Materials
Popsicle sticks (1200)
Elmer’s glue (6 bottles)
Toothpicks (1 box)
Design Notebooks (1 per student)
Pencils (1 per student)
Paper Plates (12)
String (6 balls)
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Include specific scientific information relevant to the task (i.e., comprehensive explanations of the “science concepts” and how they are related). Include graphics, illustrations, or concept maps. List relevant web sites.
Note any special materials or procedures that need to be included or followed.
Procedures:
The students should be divided into design teams, with four students in each team. It is important that students are grouped into teams, as it allows them to compare their initial individual ideas with the ideas from other students in the group. This collaboration allows for students to be able to develop more complex ideas as well as teamwork skills. Encourage the students to be open to other designs and perspectives as well as the role of compromise in design projects. Each student should contribute equally in the design process throughout the lessons. To ensure that each student participates, have the students record exactly how they contributed to the final product in their Engineering Design Notebooks.
Background Information:
Source: http://tryengineering.org/lessons/popsiclebridge.pdf
Type of Bridge
Arch
Characteristics
Arch bridges are arch-shaped and have abutments at each end. The earliest known arch bridges were built by the Greeks and include the
Arkadiko Bridge. The weight of the bridge is thrusted into the abutments at either side.
Examples
The largest arch bridge in the world, scheduled for completion in 2012, is planned for the Sixth Crossing at
Dubai Creek in Dubai, United Arab
Emirates.
Beam
Suspension
Truss
Beam bridges are horizontal beams supported at each end by piers. The earliest beam bridges were simple logs that sat across streams and similar simple structures. In modern times, beam bridges are large box steel girder bridges. Weight on top of the beam pushes straight down on the piers at either end of the bridge.
Suspension bridges are suspended from cables. The earliest suspension bridges were made of ropes or vines covered with pieces of bamboo. In modern bridges, the cables hang from towers that are attached to caissons or cofferdams which are embedded deep in the floor of a lake or river.
Truss bridges are composed of connected elements. They have a solid deck and a lattice of pin-jointed girders for the sides. Early truss bridges were made of wood, but modern truss bridges are made of metals such as wrought iron and steel.
Beam bridges were commonly used for railroad travel, and are abundant in Ohio and Mississippi.
The longest suspension bridge in the world is the 3911 m (12,831ft.)
Akashi Kaikyo Bridge in Japan.
Another example of a suspension bridge is the Golden Gate Bridge in
San Francisco, California.
The Quebec Bridge is also the world's longest truss bridge.
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bridges?
Time: One 40-minute session
Procedures / Steps:
1.
Prepare a set of index cards for each team. Each set should contain cards four total. A type of bridge will be written on each card. Hang a picture of each type of bridge at the front of the room. The teams will be given five minutes to discuss which type of bridge matches which picture that is hanging. At the end of the time, have the students place their card, using a magnet, under the picture for the type of bridge it matches.
2.
Hold a discussion about their responses. Ask students the questions listed below, and go through each bridge, discussing its characteristics and what type of bridge the students think it is.
ASK: Raise your hand if you have seen one or more of these bridges before. What are some unique characteristics or features of bridges? How did your group decide how to categorize the bridges? Based on what features? Why do you think this bridge is this type? Does any group want to change their responses?
3.
After hearing students’ ideas, discuss each type of bridge and why it is that type. Hand out the Engineering Design Notebooks, and have the students take notes on the information. For each bridge, discuss specific characteristics, provide pictures, and give examples using PowerPoint.
ASK: What is one job or function of a bridge? How are bridges important in presentday society? Can someone give me an example of a bridge here in town? What would happen if that bridge was not there?
4.
Introduce science concepts: load, span, and model. Discuss as a class what each of these terms means and how they are important in the design and construction of bridges.
ASK: What do you think load means? What do you think span means? What do you think model means?
5.
Explain the importance of models in terms of developing a prototype before using resources to build the actual object. Have students record important vocabulary and definitions in their notebooks.
DISCUSS: Because bridges are used for transportation and a means of getting from one place to another, it is important to consider the weight it can hold. The weight a bridge can hold is dependent on its design. The span of the bridge is the distance between the
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two objects at each end of the bridge. Models can help us see a smaller version of the final design before building.
ASK: Why is it important to consider the load a bridge can hold? How is span different from length? Is it important to have a bridge that is longer than its span? Why is it important to develop models?
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Time: 45 minutes
Procedures / Steps:
1.
Review material from previous lesson. Hold a discussion about what students remember about the types of bridges and the application of the science content to bridges.
ASK: Name a type of bridge and explain why it is this type. Why do you think load is an important factor to consider when designing a bridge? Why are there different types of bridges? What other factors are important to consider when designing bridges?
2.
Introduce the Design Task by passing out the Design Brief and reading it as a class
(attached at the end). Pass out Engineering Design Notebooks, and have the students set up the task. Walk them through this process.
ASK: What is the problem? Who is the client? Who is the user? What are the constraints? What are the materials?
3.
Instruct students to design their own plan for the bridge. Tell them to include size estimations, estimate of the number of Popsicle sticks, cost of the design, and length of the bridge Show students the rice that will be used as weights. Give them 10 minutes to complete this individually. Instruct the students to develop a team plan. Students must include a second drawing while including the information listed above. Give them 15 minutes to discuss ideas and develop the team plan.
4.
Wrap-up and explain that students will be building their designs during the next lesson.
Review important elements needed for bridges by asking students to double-check their designs.
ASK: Did you remember to think about load when designing your bridge? What is the span of your bridge? What type of bridge did you base your design off of? Why did you choose this type?
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Time: 35 minutes
Procedures / Steps:
1.
Have students get out their Engineering Design Notebooks and ask them to review their plans.
ASK: How are you going to divide up the work when building the bridge? Who is responsible for the materials? Who is responsible for recording? Who is responsible for checking whether or not your team is meeting the client’s needs? How will it be assembled? Discuss a strategy with your team.
2.
Provide each group with the materials and instruct them to build their design. Remind them to keep track of the total number of Popsicle sticks used and length of string used, and record this information in the Results section of the notebooks. Students should also record the length of the bridge, in centimeters. Give students 30 minutes to build and record information.
3.
Instruct students to place their bridges in the “drying location” to allow the glue to dry.
Tell the students that we will test the bridges during the next lesson.
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Time: 45 minutes
Procedures / Steps:
1.
Have students get their bridges. Each team will present their prototype to the class and discuss which type of bridge they based their design off of and why. One by one, each team will test their design. Have the students place their bridges spanning the two tables that are 40 cm apart. Have students place the weights (bags of rice) on the bridge. Put as many bags as it will hold, until one piece breaks. Students should record the data in their
Engineering Design Notebook under the Results section. On the board, write down the amount of weight each team’s bridge held.
2.
Ask each team how many Popsicle sticks they used and what the final cost of their bridge was. Put this information on the board next to the amount of weight their bridge held.
Discuss which bridges were they most successful in relation to the requirements of the design brief.
ASK: Which bridge held the most? Which bridge was the cheapest? Which used the least number of Popsicle sticks? Which bridge was the most aesthetically pleasing?
Which bridge was the most cost efficient?
3.
Have the students complete the Conclusion section individually. Provide them with the guiding questions, listed below. Give students 20 minutes to complete this.
GUIDING QUESTIONS:
1. Was your bridge successful? Why or why not?
2. Did you choose a good type of bridge to base your design on? Why or why not?
3. How is your design different or similar to this type of bridge?
4. You created a prototype of the bridge. The real bridge must be scaled to be real size. The real bridge must span a distance that is 854.75 times bigger. Based on the length of your bridge, how long will your bridge be when scaled to real size?
5. If you had the opportunity to re-design your bridge, what would you change?
6. Use the terms written on the Word Bridge at the front of the room (Span, load, and model) to write a paragraph. Explain what each term is and use these terms to describe how bridges are designed.
4. Discuss the activity as a whole with the students. Wrap-up the activity and reinforce concepts.
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ASK: What did you learn during this design task? Why is the science behind bridges important to know? What is the importance of cost in engineering? Did you like this activity? Why or why not?
The following are possible sources of formative and summative assessment:
Formative: Through the students’ answers to questions throughout the discussions, the teacher can gain a better understanding of their knowledge. Monitor their answers, clarify misconceptions, and take notes to remember what concepts to reinforce and review. Observe students initial plan and designs in their notebook, paying attention to how they label and document their design. Ask students questions about their designs, including how they are addressing the ideas of load and span in their ideas. Monitor their ideas about bridges through informal conversation.
Summative:
To assess students’ understanding of the Engineering design process, use the following rubric to assess their ability to record the plan and document the plan.
Skill Basic (0) Developing (1) Mastered (2)
Identify Problem
Identify Client
Not included; Incorrect problem included
Not included
Brief description of problem; Includes the need to build a bridge
Detailed description;
Includes need to build a bridge to transport books across a river
Incorrect client included Correct client included
Identify User Not included
Diagram of Team
Plan
Materials Estimation
Cost Estimations
Not included
Not included
Not included
Incorrect use included Correct user included
Unclear design with no direct connection to a type of bridge discussed
Clear design that demonstrates a direct connection of a type of bridge discussed
Missing information;
Unreasonable estimations
All materials correctly estimated
Missing information;
Incorrect calculations
Cost correctly estimated based on materials estimations
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Length Estimation Not included
Missing information;
Unreasonable estimations
Correctly estimated length
To assess students’ understanding of the science concepts, use the following rubric to assess their use of words from the ‘Word Bridge’ in their Conclusion section.
Skill Basic (0) Developing (1) Mastered (2)
Definition of ‘Load’
Use of ‘Load’ in
Relation to Bridges
Definition of ‘Span’
Use of ‘Span’ in
Relation to Bridges
Definition of ‘Model’
Use of ‘Model’ in
Relation to Bridges
Not included; Response unrelated to concept
Not included; Response unrelated to concept
Not included; Response unrelated to concept
Defines load is the weight of the bridge
States that load is the weight of the bridge
Defines span as the length of an object
Defines load as the amount of weight a structure can support
States that load is important to consider because it helps you know how much weight can be put on the bridge
Defines span as the distance between two specific points
Not included; Response unrelated to concept
States that span is how long to build the bridge
States that span is important to consider because it is important in determining the length of the bridge
Not included; Response unrelated to concept
Defines model as a smaller version of a real object
Defines model as a scaled version of a real object
Not included; Response unrelated to concept
States that models are used to test designs
States that models are important because you can test designs without using resources to build full scale bridges
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Activity Extensions:
Recommended Readings:

Bridges! Amazing Structures To Design, Build And Test by Carol A. Johmann and
Elizabeth J. Reith (ISBN: 978-0613277518)

Brooklyn Bridge by Lynn Curlee (ISBN: 978-0689831836)

Bridges of the World: Their Design and Construction by Charles L. Whitney (ISBN:
0486429954)
Write a paragraph about the importance of engineering in designing, creating, and using bridges.
Research the history of bridges and discuss the impact it has had on transportation and movement of goods.
Design a bridge that can hold the weight of three students, using only Popsicle sticks and glue.
Web Resources:

TryEngineering (www.tryengineering.org)

Sydney Harbor Bridge History (www.cultureandrecreation.gov.au/articles/harbourbridge)

Building Big - Bridges ( www.pbs.org/wgbh/buildingbig/bridge

How Stuff Works: How Bridges Work
( http://science.howstuffworks.com/engineering/civil/bridge.htm
)
Other Resources:

Build Your Own Bridge 1:
( http://www.learn4good.com/games/simulation/build_bridge_across_canyon.htm
)

Build Your Own Bridge 2:
( http://www.learn4good.com/games/simulation/build_bridge_across_canyon2.htm
)

Have a Civil Engineer visit the classroom to discuss the role and design of bridges
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Everlasting Bridges Inc. is building a bridge for Boiler Books to transport books across the Wabash River. Before using the resources to build the actual bridge, the company wants to see a detailed model of the bridge design. They are looking for a design that is durable, holds 5 lbs., and is aesthetically pleasing. The bridge prototype has to span 40 cm and must be made out of the provided materials- glue, string, and Popsicle sticks. The company does not want to waste money or materials, so they are looking for a design that is as cheap as possible but meets the requirements.
1.
Develop your own plan first. Record your plan in your Engineering Design
Notebook by drawing and labeling. Share your design with your team members and, working together, decide on the final design. Record the final plan in your notebook as well, by drawing and labeling the bridge. You need to estimate the amount of materials you will use.
2.
Construct a prototype of the bridge based on your team plan.
3.
Test your bridge to be sure it meets the criteria listed above.
4.
Analyze your design. Was it successful?
1 Popsicle stick = $150
1 bottle of glue = $250
10 cm string = $100
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