(taken from http://www.nps.gov/archive/crmo/chap2d.htm)
Obj. Students will be able to describe the liquids in terms of their viscosity
Students will be able to explain how heat affects a liquid's viscosity.
Students will understand the difference between a basaltic lava which is runny and
rhyolite lava which is thicker.
Materials: smooth surface like a cookie sheet or white board, water, honey, vegetable oil, heat source, refrigeration if possible, chart to record findings.
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1. On one side of the smooth surface draw a line and label it "A" and on the bottom label the other side "B".
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2. Pretend that the liquids are different lavas at varying temperatures. Record the temperature, and time that it takes for the liquids to travel from side "A" to side "B". Also record if the liquid is highly viscous (thick) or low viscous (runny).
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3. You can also record whether the liquids would be high in silica (high viscosity) or little silica (low viscosity.
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4. Note how temperature affected viscosity. Did the honey noticeably cool as it slid down the surface? If so did it look differently at the bottom than it did on top?
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5. Did any of the materials look ropey- like pahoehoe?
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6. If you extend the experiment and refrigerate some of the materials would the honey crystallize and become like jagged aa lava?