Steps to this lesson:
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1. Read this page on Viscosity. Take the time to record answers to questions (Reflecting Moments & Try It Yourself) as well as your thoughts on the videos. When you get to the bottom of the page. Transfer the answers from your notebook to the comment section. Please include your initials.
2. Once you have read through this page and you think you have a good understanding of the material, you may move onto a review activity Read the instructions carefully and complete to the best of your ability. If you have any questions, make sure you ask! It doesnt hurt to ask!
3. Finally, once you have looked through all of the web activities on density. Please log into google classroom and under the Science 8/9 tab there will be a "Viscosity Assignment". Complete the assignment and hand it in on google classroom. That assignment is for marks.
What is Vicsosity?
Fluids can flow. How quickly they can flow is called flow rate. A substance’s resistance to flow (how thick or thin it is), or viscosity, affects flow rate. The internal resistance or friction between the particles of the substance determines the viscosity of that substance. The more friction - the more viscous (thicker) a substance is. The higher the viscosity of a substance, the slower it flows.
Fluid : any substance that flows. (example : air,water, syrup)
Reflecting Moment : After viewing this picture, where would you catergorize oil? water? table syrup?
The Effect of Temperature on Viscosity
The ramp method of testing viscosity involves pouring a fluid down a ramp and timing how long it takes to get to the bottom. By pouring the same amount of another fluid and timing it, you can compare the viscosities of different fluids. You can also investigate the effect of temperature on viscosity by testing the same fluid at different temperatures
Understanding Viscosity and Temperature
Recall viscosity is a fluid's internal resistance or friction that keeps it from flowing. A fluid with a high viscosity has a large amount of internal resistance or friction. As the temperature of a liquid increases, its viscosity decreases. The opposite is also true. As the temperature of a liquid dequid decreases, the viscosity increases. If you did the ramp method activity, your data will show that the warmer the fluid, the faster it flows
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The particle model of matter can help you understand why this change in viscosity happens. Recall that in the particle model, a liquid is made of particles that can slide and roll over each other. When energy or heat is added to the liquid, the particles slide and roll more quickly. As a result , the fluid flows more readily - its viscosity decreases. The reverse is also true. The result is that the viscosity increases- the fluid flows more slowly.
Reminder: Increasing temperature lowers viscosity (makes it thinner)
Decreasing temperature increases viscosity (making it thicker)
Question : How do the particles change when something is more viscous? Do they move faster or slower? Is there more or less of them?