Students learn and discuss the advantages and disadvantages of renewable and non-renewable energy sources. They also learn about our nation's electric power grid and what it means for a residential home to be "off the grid."

In this extension to the Ohm's Law I activity, students observe just how much time it takes to use up the "juice" in a battery, and if it is better to use batteries in series or parallel. This extension is suitable as a teacher demonstration and may be started before students begin work on the Ohm's Law I activity.

Students work to increase the intensity of a light bulb by testing batteries in series and parallel circuits. They learn about Ohm's law, power, parallel and series circuits, and ways to measure voltage and current.

This lesson will allow students to explore an important role of environmental engineers: cleaning the environment. Students will learn details about the Exxon Valdez oil spill, which was one of the most publicized and studied environmental tragedies in history. In the accompanying activity, they will try many "engineered" strategies to clean up their own manufactured oil spill and learn the difficulties of dealing with oil released into our waters.

This hands-on experiment will provide students with an understanding of the issues that surround environmental cleanup. Students will create their own oil spill, try different methods for cleaning it up, and then discuss the merits of each method in terms of effectiveness (cleanliness) and cost. They will be asked to put themselves in the place of both an environmental engineer and an oil company owner who are responsible for the clean-up.

Students learn about oil spills and their environmental and economic effects. They experience the steps of the engineering design process as they brainstorm potential methods for oil spill clean-up, and then design, build, and re-design oil booms to prevent the spread of oil spills. During a reflective session after cleaning up their oil booms, students come up with ideas on how to reduce oil consumption to prevent future oil spills.

The lesson begins by introducing Olympics as the unit theme. The purpose of this lesson is to introduce students to the techniques of engineering problem solving. Specific techniques covered in the lesson include brainstorming and the engineering design process. The importance of thinking out of the box is also stressed to show that while some tasks seem impossible, they can be done. This introduction includes a discussion of the engineering required to build grand, often complex, Olympic event centers.

Students use three tracks marked on the floor, one in yards, one in feet and one in inches. As they start and stop a robot specific distances on a "runway," they can easily determine the equivalent measurements in other units by looking at the nearby tracks. With this visual and physical representation of the magnitude of the units of feet, yard and inches, students gain an understanding of what is meant by "unit conversion." They also gain a familiarity with different common units of measurement. They use multiplication and division to verify their physical estimated unit conversions. Students also learn about how common and helpful it is to convert from one unit to another in everyday situations and for engineering purposes. This activity helps students make the abstract concept of unit conversion real so they develop mental models of the magnitude of units instead of applying memorized conversion factors by rote.

Students learn that charge movement through a circuit depends on the resistance and arrangement of the circuit components. In a hands-on activity, students build and investigate the characteristics of series circuits. In another activity, students design and build a flashlight.

In this activity, students learn about ocean currents and the difference between salt and fresh water. They use colored ice cubes to see how cold and warm water mix and how this mixing causes currents. Also, students learn how surface currents occur due to wind streams. Lastly, they learn how fresh water floats on top of salt water, the difference between water in the ocean and fresh water throughout the planet, and how engineers are involved in the design of ocean water systems for human use.

Looking at models and maps, students explore different pathways and consequences of pollutant transport via the weather and water cycles. In an associated literacy activity, students develop skills of observation, recording and reporting as they follow the weather forecast and produce their own weather report for the class.

Using their knowledge of the phases of matter, the scientific method, and polymers, student teams work as if they are chemical engineers to optimize the formula for slime. Hired by the fictional company, Slime Productions, students are challenged to modify the chemical composition of the basic formula for slime to maximize its "bounce factor."

Students work in engineering teams to optimize cleaner energy solutions for cooking and heating in rural China. They choose between various options for heating, cooking, hot water, and lights and other electricity, balancing between the cost and health effects of different energy choices.

Student groups work with manipulatives—pencils and trays—to maximize various quantities of a system. They work through three linear optimization problems, each with different constraints. After arriving at a solution, they construct mathematical arguments for why their solutions are the best ones before attempting to maximize a different quantity. To conclude, students think of real-world and engineering space optimization examples—a frequently encountered situation in which the limitation is the amount of space available. It is suggested that students conduct this activity before the associated lesson, Linear Programming, although either order is acceptable.

Students learn about how a device made with dye from a plant, specifically cherries, blackberries, raspberries and/or black currents, can be used to convert light energy into electrical energy. They do this by building their own organic solar cells and measuring the photovoltaic devices' performance based on power output.

For students that have already been introduced to the water cycle this lesson is intended as a logical follow-up. Students will learn about human impacts on the water cycle that create a pathway for pollutants beginning with urban development and joining the natural water cycle as surface runoff. The extent of surface runoff in an area depends on the permeability of the materials in the ground. Permeability is the degree to which water or other liquids are able to flow through a material. Different substances such as soil, gravel, sand, and asphalt have varying levels of permeability. In this lesson, along with the associated activities, students will learn about permeability and compare the permeability of several different materials for the purpose of engineering landscape drainage systems.

The purpose of this lesson is to introduce the students to the Sun. They explore various aspects of the Sun including its composition, its interior workings, and its relationship to the Earth.

This lesson covers the topic of human bones and joints. Students learn about the skeleton, the number of and types of bones in the body, and how outer space affects astronauts' bones. Students also learn how to take care of their bones here on Earth to prevent osteoporosis or weakening of the bones.

Students are introduced to the fabulous planet on which they live. Even though we spend our entire lives on Earth, we still do not always understand how it fits into the rest of the solar system. Students learn about the Earth's position in the solar system and what makes it unique. They learn how engineers study human interactions with the Earth and design technologies and systems to monitor, use and care for our planet's resources wisely to preserve life on Earth.

Students learn about the human body's system components, specifically its sensory systems, nervous system and brain, while comparing them to robot system components, such as sensors and computers. The unit's life sciences-to-engineering comparison is accomplished through three lessons and five activities. The important framework of "stimulus-sensor-coordinator-effector-response" is introduced to show how it improves our understanding the cause-effect relationships of both systems. This framework reinforces the theme of the human body as a system from the perspective of an engineer. This unit is the second of a series, intended to follow the Humans Are Like Robots unit.