![]() Having these demonstrations in a movie format is especially good for large classes, where it might be difficult for students in the back to see what the instructor is doing on the bench top. Silica, aluminum, potassium, sodium, and calcium, forming a polymerized liquid rich in feldspar and quartz. ![]() However, if you don't feel like you have the time to spend with all the "interactive" elements, like small-group discussions and iClicker questions, you can just import the movies into your own Powerpoint and use them however you like. describes the internal friction of a moving fluid. Mudflows occur on steep slopes where vegetation is not sufficient to prevent rapid. Its high viscosity will not allow it to flow as far as a water flow. It has a higher density and viscosity than a streamflow and can deposit only the coarsest part of its load this causes irreversible sediment entrainment. The Powerpoint should be pretty self explanatory in terms of the progression of ideas I take the students through. : the quality or state of being viscous : a sticky or glutinous consistency 2 a technical : the property of resistance to flow in any material with fluid properties water has a small but measurable viscosity, or 'stickiness,' which results from the weak mutual attraction of water molecules. Viscosity is a measure of a fluids resistance to flow. mudflow, flow of water that contains large amounts of suspended particles and silt. My ultimate goal is to get them to the point that they can pick up a piece of basalt, identify it, and make up a fairly complete story about how it originated, referring back to basic physical and chemical principles, when appropriate. The resistance of a fluid to flow, where a high value means a fluid which does not like to flow (like toothpaste), and a low value means a fluid which flows easily (like water). This illustrates why runny lavas make shield volcanoes and flood basalts, but more viscous magmas make tall, pointy cones. The toothpaste comes out and piles up on itself, rather than running down the sides very far. The water runs out and spreads out because it isn't very viscous. The second demo is a movie of me shooting water up out of an inverted funnel, and then shooting out toothpaste. The crystal structure demos illustrate the idea that more silica = more polymerization. They also have a harder time making it to the surface and don't spread out as much once they are erupted. An eruption of highly viscous (very sticky) magma tends to produce steep-sided volcanoes with slopes that are about 3035°. More viscous magmas build up gas pressure more readily, and so are more explosive. Likewise, silica molecules in magmas and minerals like to polymerize, so the more silica there is, the more viscous the magma, and when it's hotter, it becomes less viscous. The crystallization of two magmas of a nearly identical chemical composition into two different mineral aggregates as a result of different cooling. They stick together less readily when heated. The point is that sugar molecules make the liquid more viscous, because they like to stick together. Higher SiO2 (silica) content magmas have higher viscosity than lower SiO2. The first demo is a movie of me blowing air into a beaker of water, then a beaker of honey, and then a beaker of heated honey. Viscosity depends on primarily on the composition of the magma, and temperature. (Why are some volcanoes more explosive than others? Why are particular surface features associated with particular kinds of volcanoes? Why does basaltic magma have an easier time making it to the surface?) It's this kind of connected knowledge that students will have a better chance of retaining and being able to use after the class is over. (Top) 1 Etymology 2 Definition Toggle Definition subsection 2.1 Dynamic viscosity 2.2 Kinematic viscosity 2. 1 dyne/cm2 between the ends of the sample causes a fluid with a dynamic viscosity of 1 poise to flow at a rate of 1 cm3/s (Fig. With this activity, I try to help them see that all the stuff they learned earlier about molecules, phases of matter, silicate crystal structures, and igneous rock classification can help them understand the different types of volcanoes. It's just a mass of disconnected facts that they have to memorize. One of the main problems I face is that many of my students treat material from different chapters in the textbook as completely separate information.
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