Lesson 1

Grade:  Level:  5

Subjects:  Language Arts, Science, Technology

Learner Outcomes:  Students will Identify four basic bridge types:  arch, beam, suspension, and cable-stayed.  They will understand the benefits and drawbacks of different types of bridges, as well as think about the challenges involved in building bridges.

Materials: 


Technology Tools/Courseware: computer with Internet capability
 

  • Teacher Notes:
    • Bridge classification can be done individually or in groups.
    • Bridge pictures will work best if printed from a color printer.
    • Activities may be done in groups or as a classroom demonstration.
    • A Bridge Glossary has been provided for teacher and/or student use.


    Procedure: 

    • As a class, brainstorm a list of known bridges.
    • Handout Bridge Pictures Handout
    • Working independently, students cut apart the pictures of bridges and classify them into groups of their choosing.
    • As a group, students will share their classification and the reasoning behind their choices.
    • Introduce the four basic bridge type using Basic Bridge Types Handout
    • Discuss handout and note vocabulary
    • Complete activity "How Do Abutments Support an Arch Bridge"
       
      Illustration of carboard bending Cut a strip of cardboard that's a bout one  inch by 11 inches. Gently bend the strip so that it has a curve. Position the cardboard
      on a table so that it resembles an arch. Press down on the center of the arch.
      What happens to the ends of the cardboard?

       
       
      Next, place a stack of books at each end of the arch. Press again. Now what happens?
      Notice how the stacks of books act as abutments, keeping the ends of the arch from spreading apart.

       
    • Complete Activity "What Happens When a Load Pushes Down on a Beam Bridge"

    •  
      Take a flat eraser or a small sponge and slice a shallow notch across the top and bottom. Create a beam bridge by supporting each end of the eraser (or sponge) with a stack of books. Press down on the center of the bridge. What happens to the top and bottom notches? Notice how the top notch squeezes together in compression, while the bottom notch spreads apart under tension.

       
       
    • Complete Activity "What Are Anchorages for?"

    • Tie two loops of string around the tops of two hard 
      cover books of similar size. Tie a third piece of
      string to each loop so that it hangs loosely between
      the books. Press down on the center string. What happens?

       
      Next, stand two books about 10 inches apart. Put a stack of heavy books on one end of string to secure it to the table. Then pass the string over each book (letting some string hang loosely between the books). Place a second stack of books on the other end of the string. Press again on the center of the string. What happens? Notice how the anchorages (stacks of books) help to stabilize the bridge.

       
       
    • Complete Activity "How Do Cable-Stayeds Work?"

    •  
       Try making cable-stayeds to support your arms. Take a piece of rope (about five feet long), and have a partner tie each end of the rope to each of your elbows. Then lay the middle of the rope on top of your head. The rope acts as a cable-stayed and holds your elbows up.
      Have your partner tie a second piece of rope (about 6 feet long) to each wrist. Lay the second rope over your head. You now have two cable-stayeds. Where do you feel a pushing force, or compression?  Notice how the cable-stayeds transfer the load of the bridge (your arms) to the tower (your head).
    • Students will create a bridge dictionary including the definition and illustration/example for the following words:  arch, abutment, anchorage, beam bridge, cable, cantilever bridge, compression, deck, engineer, girder, span, stayed, stress, suspension bridge, tension, torsion,

    • tower, truss
    Modifications:  Make modifications based on student IEP. 

    Enrichment Activities:  Students may participate in the on-line labs at PBS/Building Big to discover how forces affect structures.  Students may enrich their vocabulary of bridge terms by logging on to About Bridges.

    Evaluation/Assessment: Complete Bridge Vocabulary Puzzle
     
     

    WV State IGOs:
    Language Arts
    Science
    5.32, 5.36 5.1, 5.2, 5.3, 5.7, 5.13

    National Standards:
    Language Arts
    Science
    7.2.1, 7.2.6 10.2.6, 13.2.3

    References:



    Authors:
    Renee Anderson
    Linda Cline
    Anita Pugh
     
     

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