Sara E. Thomas
Canoes are made out of a variety of materials such as steel, aluminum, wood, fiberglass and even plastic. The best material depends on where and how the boat will be used. A canoe for white water canoeing will be designed very differently than one which will be used on calm lakes for fishing. First we will look at the canoe without a rower. A canoe is the simplest of boat forms - a basic hollowed out hull with benches as seating. We are primarily concerned with the form of the hull. I would like students to consider which variables (things that can be changed) affect the speed of the boat? Simply by looking at the construction of the hull how could you change the speed of the boat?
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- Materials
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- Weight
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- Shape
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- Texture
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- Symmetry
When the hull of the boat comes into contact with the water, water molecules become stuck to the hull from friction. This friction with the water is what slows the boat down. There are two ways to lessen the amount of friction. First is to lower the amount of surface area touching the water. The less area touching water, the less friction, and the faster the boat will move. (This is why many speed boats “plane out”; once they are moving at higher speeds much of the hull is out of the water so the boat can move much more quickly.) The second is by designing the hull so that water can easily move around it. The film of water molecules stuck to the hull from friction builds and thickens until it reaches the stern where it breaks. This is why the boat appears to be cutting through the water. (Winters, as the water passes)
Students will be challenged to choose from a variety of hull types, materials, textures, etc. to design the fastest boat. Students will create a hypothesis predicting which combination of materials, textures, shapes and design will create the fastest canoe. Students will create plans for their canoe learning important boat terminology. They will then build the plan they think will create the fastest boat and we will race the boats to see which variables make the largest difference.