Matchcard Science© Technology - 1 Diagram Four Different Types of Bridges

MatchCard Science© Technology - 1 Diagram four different types of bridges.

©Learn For Your Life Publishing www.Learn4YourLife.com MatchCard Science© Answer Key Technology - 1 Diagram four different types of bridges.

BEAM ARCH

Weight of the beam Weight is spread evenly pushes straight down

PIERS ABATEMENTS Supports the weight of the Foundations anchored main beam firmly in the ground

TRUSSES Patterned rods that strengthen the main beam CABLE CANTILEVER SUSPENSION Attached to the on any type of bridge ground beyond the Made up of sections Able to span wide and towers in order to span large high distances; often distances over waterways so ships can sail underneath

CENTRAL PIER Supports the weight of one section of the bridge DECK Hangs from large cables above

©Learn For Your Life Publishing www.Learn4YourLife.com MatchCard Science© Learning Activities Technology - 1

Building Bridges Arch Bridge Suspension Bridge Before looking at the Matchcard, the students To make an arch bridge you may need to raise I always thought they were called suspension can experiment with ways to build bridges to or lower the height of your bridge by changing bridges because everyone in the car was in sus- make them stronger. You will need: the number of books. pense when we crossed them. Not really. But if • A stack of books (they act as the piers) Take another index card and bend it into I had known they were called suspension bridges • Some index cards (bridge supports) an arch and set it under the beam of your beam because the entire bridge and all those cars were • Toy cars - Matchbox size is fine bridge. The arch will take the weight and spread being suspended from the upper beams I would • Yarn or string (tooth floss will also work) it out. have been in even more suspense. • Tape Now try driving your two cars on the First, take the piers that were built for the bridge. You will notice that the index card is cantilever bridge and turn them into the towers of stronger. the suspension bridge. They will be place on either Let’s Start with a Beam Bridge Point out that bridges may have a series side of each edge of the index card. The triangle Make two stacks of books the same size and of arches. Some of the arches may be on top should be pointing out and away from the middle close enough together that an index card can rather than underneath the beams, but they will of the bridge. span the space between. There’s your beam learn about that coming up. Cut two little snips in the outer corner bridge. of the triangular towers. This will help hold the Drive a car across the bridge. The index Cantilever Bridge string. card may sag a bit, but the bridge should hold. Sometimes bridges have to span long distances, Using a hole punch or a sharp pencil, punch What if you added a second car? It’s probably for instance when crossing a wide river. You four small holes in the index cards. Punch the getting a bit shakey. I wouldn’t want to be in can demonstrate this by taping two index cards holes in the middle of each edge of the card. one of those cars if it was a real bridge. together and increasing the space between your Small Snip x4 So what would you do? books. You know this isn’t going to hold your toy car. So we need to make the central pier. Fold an index card in 3rds and tape it to make a You will need to cut two long pieces of string. They should be long enough to go over Experiment Time triangular post. Make three more triangular piers. Slide both towers, across the stack of books, and reach Let the student(s) experiment a little with the to the table top. Make sure the strings are thread- index cards and see what ideas they have for them under each the center of each index card on both sides. They are called central piers ed into the little slits that were cut into the towers. making a stronger bridge. Than we will build This helps hold them in place. the next three types. because they are in the middle of the section. You may need to adjust the number of (Suspension Bridge Continued On Next Page) books to make the bridge the right height for your piers.

Suspension Bridge, continued Poster Bridge Building Kits Tape the four edges of the cable firmly to There are some truly amazing and Commercial bridge building kits are available. the table top with tape. beautiful bridges all around the world. Look You might even do a bridge science fair exper- Now we need to attach the index card on the internet for different pictures of large iment or compete in a local contest. beams to the cable suspended from the towers. and famous bridges. Cut four more pieces of string about 12 inches Print some of the pictures and make long. This is longer than needed, and will be a poster showing samples of the four types of trimmed later. But shorter string will be harder bridges. Science Fair Idea to work with. Balsa wood is popular for building bridge Thread one of the stings through the models. Try this experiment. hole in the index card. Then tie it at the age of What is the difference in the amount Local Bridges card with two simple knots. of weight a bridge can hold if you add an While there are truly spectacular Now take the other end of the string and arch? All other dimensions must be the same. loop it around the cable above. Trying to tie a bridges in major cities around the world, it is knot the right length can be difficult. Instead, quite likely that you barely notice the bridges loop it five times around the cable. Then lash it your car travels over day in and day out. to the vertical string by going around the upper Notice the bridges now. Stop and take horizontal cable then around the shorter verti- pictures if you are able. What type of bridges cal cable five times. That should hold it. are most popular in your area? Repeat the process with the other three index cards. You now have the index card suspended by the cables. Drive your toy car over it. What Trusses is holding the weight of the car? What holds Trusses are triangular rods that give your weight when you drive over a suspension additional strength to the bridge. They are bridge? often on the side and act as a railing as well as a source of support. What patterns of trusses can you find on the bridges in your area.

BEAM PIERS T-1 T-1 ABATEMENTS To Make Your MatchCard more durable: ARCH T-1 T-1 CENTRAL PIER 1. Put the student MatchCard in a clear plastic CANTILEVER T-1 page protector. T-1 TRUSSES T-1 SUSPENSION 2. Laminate the information pieces. You can also T-1 CABLE T-1 make them sturdier by covering the paper with Weight of the beam transparent tape prior to cutting the pieces out. DECK pushes straight down T-1 T-1 3. For more ideas on how to use the MatchCards, Weight is spread evenly Supports the weight of the and for keeping a notebook for review, see the T-1 main beam Instructor’s Guide. Made up of sections T-1 Foundations anchored firmly in order to span large 4. The complete Technology Unit Study provides distances in the ground T-1 T-1 the student worksheets, answer key, and teaching Able to span wide and Supports the weight of one activities for this and 5 other objectives. See the section of the bridge website for more information. high distances; often T-1 over waterways so ships Patterned rods that can sail underneath strengthen the main beam T-1 on any type of bridge T-1 Attached to the ground beyond the towers T-1 Hangs from large cables above T-1