In this lesson, students will explore the causes of water pollution and its effects on the environment through the use of models and scientific investigation. In the accompanying activities, they will investigate filtration and aeration processes as they are used for removing pollutants from water. Lastly, they will learn about the role of engineers in water treatment systems.

This lab demonstrates Hooke's Law with the use of springs and masses. Students attempt to determine the proportionality constant, or k-value, for a spring. They do this by calculating the change in length of the spring as different masses are added to it. The concept of a spring's elastic limit is also introduced, and the students test to makes sure the spring's elastic limit has not been reached during their lab tests. After compiling their data, they attempt to find an average value of the spring's k-value by measuring the slopes between each of their data points. Then they apply what they've learned about springs to how engineers might use that knowledge in the design of a toy that enables kids to jump 2-3 feet in the air.

To get a better understanding of complex networks, students create their own, real social network example by interacting with their peers in the classroom and documenting the interactions. They represent the interaction data as a graph, calculate two mathematical quantities associated with the graph—the degree of each node and the degree distribution of the graph—and analyze how these quantities can be used to infer properties of the social network at hand.

Students act as chemical engineers and use LEGO® MINDSTORMS® NXT robotics to record temperatures and learn about the three states of matter. Properties of matter can be measured in various ways, including volume, mass, density and temperature. Students measure the temperature of water in its solid state (ice) as it is melted and then evaporated.

Students work through an online tutorial on MIT's App Inventor to learn how to create Android applications. Using those skills, they create their own applications and use them to collect data from an Android device accelerometer and store that data to databases. NOTE: Teachers and students must have a working knowledge of basic programming and App Inventor to complete this lesson. This lesson is not an introduction to MIT's App Inventor and is not recommended for use without prior knowledge of App Inventor to produce an end product. This lesson is an application for App Inventor that allows for the storage of persistent data (data that remains in memory even if an app is closed). This required prior knowledge can come from other experiences with the App Inventor. Also, many additional resources are available, such as tutorials from MIT. This lesson could also be used as an enrichment project for students who are self-motivated to learn the App Inventor software.

In this activity, students build a water filter with activated carbon, cotton and other materials to remove chocolate powder from water.

Students are introduced to Hooke's law as well as stress-strain relationships. First they learn the governing equations, then they work through several example problems, first individually, then as a class. Through the lesson's two-part associated activity, students 1) explore Hooke's law by experimentally determining an unknown spring constant, and then 2) apply what they've learned to create a strain graph depicting a tumor using Microsoft Excel®. After the activities, the lesson concludes with a stress-strain quiz to assess each student's comprehension of the concepts.

Students learn about contact stress and its applications in engineering. They are introduced to the concept of heavy loads, such as buildings, elephants, people and traffic, and learn how those heavy loads apply contact stress. Through the analysis of their own footprints, students determine their contact stress.

Students act as surgical residents for the day. Working in teams, they use surgical instruments to complete tasks that are inside of a box, hidden from direct view. They are able to see inside of the box with the help of a "laparoscope" (webcam and flashlight). This engaging activity shows students one application of engineered medical instrumentation and gives them first-hand experience in seeing how form fits function. They also learn that an engineer's job does not end with a finished product because s/he must train others to use the device correctly.

Students explore how pendulums work and why they are useful in everyday applications. In a hands-on activity, they experiment with string length, pendulum weight and angle of release. In an associated literacy activity, students explore the mechanical concept of rhythm, based on the principle of oscillation, in a broader biological and cultural context in dance and sports, poetry and other literary forms, and communication in general.

Students measure different types of small-sized beams and calculate their respective moments of inertia. They compare the calculations to how much the beams bend when loads are placed on them, gaining insight into the ideal geometry and material for load-bearing beams.

Students conduct several simple lab activities to learn about the five fundamental load types that can act on structures: tension, compression, shear, bending, and torsion. To learn the telltale marks of failure caused by these load types, they break foam insulation blocks by applying these five load types, carefully examine each type of fracture pattern (break in the material) and make drawings of the fracture patterns.

Students gain experience using the software/systems (engineering) design process, specifically focusing on the testing phase. This problem-based learning activity uses the design process to solve open-ended challenges. In addition to learning about test cases for testing software, students utilize the design process as a vehicle to work through a problem and arrive at a solution.

JUnit is a testing method that is included with NetBeans (Java) installs or can be downloaded from the web and included in the Java build. In this activity, students design tests for a provided Java class before the class methods are constructed using a process called test-driven development. To create a design, the software/system design process, which is a specific case of the engineering design process, is followed. After students create a design, it is implemented and tested and if necessary, the design undergoes editing to make sure it functions by testing the Java class correctly. To conclude the activity, students write the methods in the Java class using their tests to debug the program.

Prior to reaching households, water is exposed to a variety of treatments designed to render it fit for human consumption and use. One of the first treatment steps is the removal of suspended solids using chemical additives called flocculants. In this activity, students learn about two commonly used flocculants and clean water collected from a local pond or river. They experiment with flocculant, stirring and pH variables.

Maps are designed to allow people to travel to a new location without a guide to show the way. They tell us information about areas to which we may or may not have ever been. There are many types of maps available for both recreational and professional use. A navigator uses a nautical map, while an engineer might use a surveyor's map. Maps are created by cartographers, and they can be very specific or very general, depending on their intended use. The focus of this lesson is on how to read and use topographical maps. Students will also learn to identify the common features of a map. Through the associated activities, students will learn how to use a compass to find bearing to an object on a map and in the classroom.

Students learn about traffic lights and their importance in maintaining public safety and order. Using a Parallax® Basic Stamp 2 microcontroller, students work in teams on the engineering challenge to build a traffic light with a specific behavior. In the process, they learn about light-emitting diodes (LEDs), and how their use can save energy. Students also design their own requirements based on real-world observations as they learn about traffic safety and work towards an interesting goal within the realm of what is important in practice. Knowledge gained from the activity is directly transferrable to future activities, and skills learned are scalable to more ambitious class projects.

Students learn about the fundamental strength of different shapes, illustrating why structural engineers continue to use the triangle as the structural shape of choice. Examples from everyday life are introduced to show how this shape is consistently used for structural strength. Along with its associated activity, this lesson empowers students to explore the strength of trusses made with different triangular elements to evaluate the various structural properties.

Students investigate the relationships between angles and side lengths in right triangles with the help of materials found in the classroom and a mobile device. Using all or part of a meter stick or dowel and text books or other supplies, students build right triangles and measure the angles using a clinometer application on an Android® (phone or tablet) or iOS® device (iPhone® or iPad®). Then they are challenged to create a triangle with a given side length and one angle. The electronic device is used to measure the accuracy of their constructions.

Students explore the response of springs to forces as a way to begin to understand elastic solid behavior. They gain experience in data collection, spring constant calculation, and comparison and interpretation of graphs and material properties to elucidate material behavior. Conduct this activity before proceeding to the associated lesson.