Garden Poles--Building Out

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What It Is (continued)

During the building process, students should be encouraged to test the strength, stability, and durability of the structures they are constructing. At the end of the building process, students should have the opportunity to observe and discuss each other's structures. For challenges involving strength, hang weights to test the strength of each structure one by one, so that the students as a class can observe what works and what doesn't.

Aesthetics is a particularly important criterion for these structures. Aesthetics is not just how pretty a structure is, but also how it makes the observer feel. Is the structure rigid and strong looking? Does it have a pleasing curve to it? Is it open, light, and airy? Does it create a feeling of tension, as if something is about to happen? Does it create an image of movement? These garden pole structures may be considered sculptures and looked at in those terms.

Discussing Results

After the initial session, have the students share their free exploration results with the whole class. Record their discoveries on the chalkboard or chart paper; students may also record drawings of structures, observations, and questions in science logs.

  • What did they experience and discover while building?

  • What difficulties did they encounter and how did they resolve them?

  • What questions do they have as a result of the activity?

  • What would they change if they were to build it again?

    The final building session is followed by weight testing, measurement, and discussion.

  • What did they observe happening?

  • If their structure was wobbly, how did they stabilize it?

    Often when building cantilevers, the problem of sideways twisting arises. These large-scale cantilevers are very susceptible to this, and many have a strong tendency to do anything but stay straight. Look for these challenges and ask students how they dealt with it.

    Most of these cantilever structures will not hold much weight. In structures that are tested with weights, raising questions like the following can help the students see some of the implications of what they are doing:

  • How many weights can be hung before the structure collapses?

  • Does it matter where the weights are hung?

  • Will the structure be more likely to collapse if the weights are hung in one place or spread out?

  • Predict where you think the structure will weaken first. Can that area be strengthened so that another area will collapse first?

    Questions about which poles are being bent and where poles are being pulled out of their taped joints help locate the tension and compression elements in these structures. Often, a long line of poles at the top of a structure will be in tension and a long line of poles along the bottom will be in compression.

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