At this point in the unit, students have learned about Pascal's law, Archimedes' principle, Bernoulli's principle, and why above-ground storage tanks are of major concern in the Houston Ship Channel and other coastal areas. In this culminating activity, student groups act as engineering design teams to derive equations to determine the stability of specific above-ground storage tank scenarios with given tank specifications and liquid contents. With their floatation analyses completed and the stability determined, students analyze the tank stability in specific storm conditions. Then, teams are challenged to come up with improved storage tank designs to make them less vulnerable to uplift, displacement and buckling in storm conditions. Teams present their analyses and design ideas in short class presentations.

Students are provided with an introduction to above-ground storage tanks, specifically how and why they are used in the Houston Ship Channel. The introduction includes many photographic examples of petrochemical tank failures during major storms and describes the consequences in environmental pollution and costs to disrupted businesses and lives, as well as the lack of safety codes and provisions to better secure the tanks in coastal regions regularly visited by hurricanes. Students learn how the concepts of Archimedes' principle and Pascal's law act out in the form of the uplifting and buckling seen in the damaged and destroyed tanks, which sets the stage for the real-world engineering challenge presented in the associated activity to design new and/or improved storage tanks that can survive storm conditions.

Students experiment with a new material—aerogel. Aerogel is a synthetic (human-made) porous ultra-light (low-density) material, in which the liquid component of a gel is replaced with a gas. In this activity, student pairs use aerogel to simulate the environmental engineering application of cleaning up oil spills. In a simple and fun way, this activity incorporates density calculations, the material effects of surface area, and hydrophobic and hydrophilic properties.

Aerogel, commonly called "frozen smoke," is a super-material with some amazing properties. In this lesson and its associated activity, students learn about this silicon-based solid with a sponge-like structure. Students also learn about density and how aerogel is 99.8% air by volume, making it the lightest solid known to humans! Further, students learn about basic heat transfer and how aerogel is a great thermal insulator, having 39 times more insulation than the best fiberglass insulation. Students also learn about the wide array of aerogel applications.

Students are introduced to Pascal's law, Archimedes' principle and Bernoulli's principle. Fundamental definitions, equations, practice problems and engineering applications are supplied. A PowerPoint® presentation, practice problems and grading rubric are provided.

In this lesson, the students will discover the relationship between an object's mass and the amount of space it takes up (its volume). The students will also learn about the concepts of displacement and density.

Students follow the steps of the engineering design process as they design and construct balloons for aerial surveillance. After their first attempts to create balloons, they are given the associated Estimating Buoyancy lesson to learn about volume, buoyancy and density to help them iterate more successful balloon designs.Applying their newfound knowledge, the young engineers build and test balloons that fly carrying small flip cameras that capture aerial images of their school. Students use the aerial footage to draw maps and estimate areas.

After learning, comparing and contrasting the steps of the engineering design process (EDP) and scientific method, students review the human skeletal system, including the major bones, bone types, bone functions and bone tissues, as well as other details about bone composition. Students then pair-read an article about bones and bone growth and compile their notes to summarize the article. Finally, students complete a homework assignment to review the major bones in the human body, preparing them for the associated activities in which they create and test prototype replacement bones with appropriate densities. Two PowerPoint(TM) presentations, pre-/post-test, handout and worksheet are provided.

Students create and analyze composite materials with the intent of using the materials to construct a structure with optimal strength and minimal density. The composite materials are made of puffed rice cereal, marshmallows and chocolate chips. Student teams vary the concentrations of the three components to create their composite materials. They determine the material density and test its compressive strength by placing weights on it and measuring how much the material compresses. Students graph stress vs. strain and determine Young's modulus to analyze the strength of their materials.

When will objects float and when will they sink? Learn how buoyancy works with blocks. Arrows show the applied forces, and you can modify the properties of the blocks and the fluid.

Students conduct a simple experiment to see how the water level changes in a beaker when a lump of clay sinks in the water and when the same lump of clay is shaped into a bowl that floats in the water. They notice that the floating clay displaces more water than the sinking clay does, perhaps a surprising result. Then they determine the mass of water that is displaced when the clay floats in the water. A comparison of this mass to the mass of the clay itself reveals that they are approximately the same.

After completing the associated lesson and its first associated activity, students are familiar with the 20 major bones in the human body knowing their locations and relative densities. When those bones break, lose their densities or are destroyed, we look to biomedical engineers to provide replacements. In this activity, student pairs are challenged to choose materials and create prototypes that could replace specific bones. They follow the steps of the engineering design process, researching, brainstorming, prototyping and testing to find bone replacement solutions. Specifically, they focus on identifying substances that when combined into a creative design might provide the same density (and thus strength and support) as their natural counterparts. After iterations to improve their designs, they present their bone alternative solutions to the rest of the class. They refer to the measured and calculated densities for fabricated human bones calculated in the previous activity, and conduct Internet research to learn the densities of given fabrication materials (or measure/calculate those densities if not found online).

Students observe Pascal's law, Archimedes' principle and the ideal gas law as a Cartesian diver moves within a closed system. The Cartesian diver is neutrally buoyant and begins to sink when an external pressure is applied to the closed system. A basic explanation and proof of this process is provided in this activity, and supplementary ideas for more extensive demonstrations and independent group activities are presented.

Students use a small quantity of modeling clay to make boats that float in a tub of water. The object is to build boats that hold as much weight as possible without sinking. In the process of designing and testing their prototype creations, students discover some of the basic principles of boat design, gain first-hand experience with concepts such as buoyancy and density, and experience the steps of the engineering design process.

In this first part of a two-part lab activity, students use triple balance beams and graduated cylinders to take measurements and calculate the densities of several common, irregularly shaped objects with the purpose to resolve confusion about mass and density. After this activity, conduct the associated Density Column Lab - Part 2 activity before presenting the associated Density & Miscibility lesson for discussion about concepts that explain what students have observed.

Concluding a two-part lab activity, students use triple balance beams and graduated cylinders to take measurements and calculate densities of several household liquids and compare them to the densities of irregularly shaped objects (as determined in Part 1). Then they create density columns with the three liquids and four solid items to test their calculations and predictions of the different densities. Once their density columns are complete, students determine the effect of adding detergent to the columns. After this activity, present the associated Density & Miscibility lesson for a discussion about why the column layers do not mix.

After students conduct the two associated activities, Density Column Lab - Parts 1 and 2, present this lesson to provide them with an understanding of why the density column's oil, water and syrup layers do not mix and how the concepts of density and miscibility relate to water chemistry and remediation. Topics covered include miscibility, immiscibility, hydrogen bonds, hydrophobic and hydrophilic. Through the density column lab activities, students see liquids and solids of different densities interact without an understanding of why the resulting layers do not mix. This lesson gives students insight on some of the most fundamental chemical properties of water and how it interacts with different molecules.

Students explore the densities and viscosities of fluids as they create a colorful 'rainbow' using household liquids. While letting the fluids in the rainbow settle, students conduct 'The Great Viscosity Race,' another short experiment that illustrates the difference between viscosity and density. Later, students record the density rainbow with sketches and/or photography.

Students use two different methods to determine the densities of a variety of materials and objects. The first method involves direct measurement of the volumes of objects that have simple geometric shapes. The second is the water displacement method, used to determine the volumes of irregularly shaped objects. After the densities are determined, students create x-y scatter graphs of mass versus volume, which reveal that objects with densities less than water (floaters) lie above the graph's diagonal (representing the density of water), and those with densities greater than water (sinkers) lie below the diagonal.

Students learn that buoyancy is responsible for making boats, hot air balloons and weather balloons float. They calculate whether or not a boat or balloon will float, and calculate the volume needed to make a balloon or boat of a certain mass float. Conduct the first day of the associated activity before conducting this lesson.