Students explore how sound waves move through liquids, solids and gases in a series of simple sound energy experiments. Understanding the properties of sound and how sound waves travel helps engineers determine the best room shape and construction materials when designing sound recording studios, classrooms, libraries, concert halls and theatres.

Examine a vapor pressure example using the ideal gas law. [16:02]

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Students study the physical properties of different fluids and investigate the relationship between the viscosities of liquid and how fast they flow through a confined area. Student groups conduct a brief experiment in which they quantify the flow rate to understand how it relates to a fluid's viscosity and ultimately chemical composition. They explore these properties in milk and cream, which are common fluids whose properties (and even taste!) differ based on fat content. They examine control samples and unknown samples, which they must identify based on how fast they flow. To identify the unknowns requires an understanding of the concept of viscosity. For example, heavy cream flows at a slower rate than skim milk. Ultimately, students gain an understanding of the concept of viscosity and its effect on flow rate.

Students are introduced to the similarities and differences in the behaviors of elastic solids and viscous fluids. Several types of fluid behaviors are described Bingham plastic, Newtonian, shear thinning and shear thickening along with their respective shear stress vs. rate of shearing strain diagrams. In addition, fluid material properties such as viscosity are introduced, along with the methods that engineers use to determine those physical properties.

Did you know the ancient Greeks first identified the three states of matter? Read about how the molecules differ in solids, liquids, gases, and plasma. View photographs and watch how the molecules move in each state. If you're really interested, read about a recently discovered fifth state of matter!

This article assembles free resources from the Water, Ice, and Snow issue of the Beyond Penguins and Polar Bears cyberzine into a unit outline based on the 5E learning cycle framework. Outlines are provided for Grades K-2 and 3-5.