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.

Students hypothesize whether vinegar and ammonia-based glass cleaner are acids or bases. They create designs on index cards using these substances as invisible inks. After the index cards have dried, they apply red cabbage juice as an indicator to reveal the designs.

Students learn the basics of acid/base chemistry in a fun, interactive way by studying instances of acid/base chemistry found in popular films such as Harry Potter and the Prisoner of Azkaban and National Treasure. Students learn what acids, bases and indicators are and how they can be used, including invisible ink. They also learn how engineers use acids and bases every day to better our quality of life. Students' interest is piqued by the use of popular culture in the classroom.

Momentum is not only a physical principle; it is a psychological phenomenon. Students learn how the "Big Mo" of the bandwagon effect contributes to the development of fads and manias, and how modern technology and mass media accelerate and intensify the effect. Students develop media literacy and critical thinking skills to analyze trends and determine the extent to which their decisions may be influenced by those who manipulate a few opinion leaders. Note: The literacy activities for the Mechanics unit are based on physical themes that have broad application to our experience in the world — concepts of rhythm, balance, spin, gravity, levity, inertia, momentum, friction, stress and tension.

Students are introduced to the concepts of biomimicry and sustainable design. Countless examples illustrate the wisdom of nature in how organisms are adapted for survival, such as in body style, physiological processes, water conservation, thermal radiation and mutualistic relationships, to assure species perpetuation. Students learn from articles and videos, building a framework of evidence substantiating the indisputable fact that organisms operate "smarter" and thus provide humans with inspiration in how to improve products, systems and cities. As students focus on applying the ecological principles of the previous lessons to the future design of our human-centered world, they also learn that often our practices are incapable of replicating the precision in which nature completes certain functions, as evidenced by our dependence on bees as pollinators of the human food supply. The message of biomimicry is one of respect: study to improve human practices and ultimately protect natural systems. This heightened appreciation helps students to grasp the value of industry and urban mimetic designs to assure protection of global resources, minimize human impact and conserve nonrenewable resources. All of these issues aid students in creating a viable guest resort in the Sonoran Desert.

How can you tell if harmful bacteria are in your food or water that might make you sick? What you eat or drink can be contaminated with bacteria, viruses, parasites and toxins—pathogens that can be harmful or even fatal. Students learn which contaminants have the greatest health risks and how they enter the food supply. While food supply contaminants can be identified from cultures grown in labs, bioengineers are creating technologies to make the detection of contaminated food quicker, easier and more effective.

Students read news reports and first-person accounts to imagine what it would be like to be in a blackout in a large city. They follow news reports as if the event were unfolding in real-time and keep weblogs or journals of their experience as they imagine it, taking on different roles of people who live in the city or commute there to work. They use their journal accounts to create a play or screenplay that depicts what the August 2003 blackout was like for the people in the U.S. and Canada who experienced it. Although this activity is geared towards fifth-grade and older students, it could be easily adapted for younger students.

Students will make a proportional model of blood out of red gelatin, a plastic bag, and rice. They will learn about the different components that make up blood and will investigate what happens when the arteries and veins experience buildup from cholesterol. They will then work in pairs to brainstorm ways to clean our clogged arteries.

Students study how heart valves work and investigate how valves that become faulty over time can be replaced with advancements in engineering and technology. Learning about the flow of blood through the heart, students are able to fully understand how and why the heart is such a powerful organ in our bodies.

Students are introduced to the circulatory system, the heart, and blood flow in the human body. Through guided pre-reading, during-reading and post-reading activities, students learn about the circulatory system's parts, functions and disorders, as well as engineering medical solutions. By cultivating literacy practices as presented in this lesson, students can improve their scientific and technological literacy.

Students are introduced to the challenge question, which revolves around proving that a cabinet x-ray system can produce bone mineral density images. Students work independently to generate ideas from the questions provided, then share with partners and then with the class as part of the Multiple Perspectives phase of this unit. Then, as part of the associated activity, students explore multiple websites to gather information about bone mineral density and answer worksheet questions, followed by a quiz on the material covered in the articles.

In their reading from activity 1 of this unit, students should have discovered the term "logarithm." It is at this point that they begin their study of logarithms. Specifically, students examine the definition, history and relationship to exponents; they rewrite exponents as logarithms and vice versa, evaluating expressions, solving for a missing piece. Students then study the properties of logarithms (multiplication/addition, division/subtraction, exponents). They complete a set of practice problems to apply the skills they have learned (rewriting logarithms and exponents, evaluating expressions, solving/examining equations for a missing variable.) Then they complete a short quiz covering what they have studied thus far concerning logarithms (problems similar to the practice problems). They consider how what they have learned moves them closer to answering the unit's challenge question.

Students revisit the mathematics required to find bone mineral density, to which they were introduced in lesson 2 of this unit. They learn the equation to find intensity, Beer's law, and how to use it. Then they complete a sheet of practice problems that use the equation.

Students examine an image produced by a cabinet x-ray system to determine if it is a quality bone mineral density image. They write in their journals about what they need to know to be able to make this judgment. Students learn about what bone mineral density is, how a BMD image can be obtained, and how it is related to the x-ray field. Students examine the process used to obtain a BMD image and how this process is related to mathematics, primarily through logarithmic functions. They study the relationship between logarithms and exponents, the properties of logarithms, common and natural logarithms, solving exponential equations and Beer's law.

Students learn about and experiment with the concept of surface tension. How can a paper clip "float" on top of water? How can a paper boat be powered by soap in water? How do water striders "walk" on top of water? Why do engineers care about surface tension? Students answer these questions as they investigate surface tension and surfactants.

Students create models of objects of their choice, giving them skills and practice in techniques used by professionals. They make sketches as they build their objects. This activity facilitates a discussion on models and their usefulness.

Student groups construct simple conductivity probes and then integrate them into two different circuits to test the probe behavior in solutions of varying conductivity (salt water, sugar water, distilled water, tap water). The activity culminates with student-designed experiments that utilize the constructed probes. The focus is to introduce students to the fabrication of the probe and expose them to two different ways to integrate the probe to obtain qualitative and quantitative measurements, while considering the application and utility of a conductivity probe within an engineering context. A provided handout guides teams through the process: background reading and questions; probe fabrication including soldering; probe testing and data gathering (including circuit creation on breadboard); probe connection to Arduino (including circuit creation and code entry) and a second round of testing and data gathering; design and conduct their own lab experiments that use the probes; online electrolyte/nonelectrolyte reading, short video, comprehension check and analysis questions.

Students learn about atoms and their structure (protons, electrons, neutrons) — the building blocks of matter. They see how scientific discoveries about atoms and molecules influence new technologies developed by engineers.