Students learn about the differences between types of water (surface and ground), as well as the differences between streams, rivers and lakes. Then, they learn about dissolved organic matter (DOM), and the role it plays in identifying drinking water sources. Finally, students are introduced to conventional drinking water treatment processes.
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 learn about gear ratios and power by operating toy mechanical cranes of differing gear ratios. They attempt to pick up objects with various masses to witness how much power must be applied to the system to oppose the force of gravity. They learn about the concept of gear ratio and practice calculating gear ratios on worksheets, discovering that smaller gear ratios are best for picking objects up quickly, and larger gear ratios make it easier to lift heavy objects.
Students learn about viscoelastic material behavior, such as strain rate dependence and creep, by using silly putty, an easy-to-make polymer material. They learn how to make silly putty, observe its behavior with different strain rates, and then measure the creep time of different formulations of silly putty. By seeing the viscoelastic behavior of silly putty, students start to gain an understanding of how biological materials function. Students gain experience in data collection, graph interpretation, and comparison of material properties to elucidate material behavior. It is recommended that students perform Part 1of the activity first (making and playing with silly putty), then receive the content and concept information in the associated lesson, and then complete Part 2 of the activity (experimenting and making measurements with silly putty).
Students pass around and distort messages written on index cards to learn how we use signals from GPS occultations to study the atmosphere. The cards represent information sent from GPS satellites being distorted as they pass through different locations in the Earth's atmosphere and reach other satellites. Analyzing GPS occultations enables better global weather forecasting, storm tracking and climate change monitoring.
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.
This activity simulates the extraction of limited, nonrenewable resources from a "mine," so students can experience first-hand how resource extraction becomes more difficult over time. Students gather data and graph their results to determine the peak in resource extraction. They learn about the limitations of nonrenewable resources, and how these resources are currently used.
Students learn about geotechnical engineers and their use of physical properties, such as soil density, to determine the ability of various soils to offer support to foundations. In an associated activity, students determine the bulk densities of soil samples, and assess their suitability to support foundations.
Students determine the mass and volume of soil samples and calculate the density of the soils. They use this information to determine the suitability of the soil to support a building foundation.
Students test the insulation properties of different materials by timing how long it takes ice cubes to melt in the presence of various insulating materials. Students learn about the role that thermal insulation materials can play in reducing heat transfer by conduction, convection and radiation, as well as the design and implementation of insulating materials in construction and engineering.
Students learn about the basic properties of light and how light interacts with objects. They are introduced to the additive and subtractive color systems, and the phenomena of refraction. Students further explore the differences between the additive and subtractive color systems via predictions, observations and analysis during three demonstrations. These topics help students gain a better understanding of how light is connected to color, bringing them closer to answering an overarching engineering challenge question.
Students leach organic matter from soil to create a water sample with high dissolved organic matter content (DOM), and then make filters to see if the DOM can be removed. They experience the difficulties of removing DOM from water, and learn about other processes that might make DOM removal more effective.
After conducting the associated activity, students are introduced to the material behavior of elastic solids. Engineering stress and strain are defined and their importance in designing devices and systems is explained. How engineers measure, calculate and interpret properties of elastic materials is addressed. Students calculate stress, strain and modulus of elasticity, and learn about the typical engineering stress-strain diagram (graph) of an elastic material.
Students learn about the remote sensing radio occultation technique and how engineers use it with GPS satellites to monitor and study the Earth's atmospheric activity. Students may be familiar with some everyday uses of GPS, but not as familiar with how GPS technology contributes to our ongoing need for great amounts of ever-changing global atmospheric data for accurate weather forecasting, storm tracking and climate change monitoring. GPS occultations are when GPS signals sent from one satellite to another are altered (delayed, refracted) by the atmosphere passed though, such that they can be analyzed to remotely learn about the planet's atmospheric conditions.
Students learn why shock absorbers are necessary on vehicles, how they dampen the action of springs, and what factors determine the amount of dampening. They conduct an experiment to determine the effect of spring strength and port diameter on the effectiveness of a shock absorber. Using a syringe, a set of springs, and liquids of different viscosities, students determine the effects of changing pressures and liquids on the action of a model shock absorber. They analyze their data through the lens of an engineer.
Students learn about solar energy and how to calculate the amount of solar energy available at a given location and time of day on Earth. The importance of determining incoming solar energy for solar devices is discussed.
Students explore energy efficiency, focusing on renewable energy, by designing and building flat-plate solar water heaters. They apply their understanding of the three forms of heat transfer (conduction, convection and radiation), as well as how they relate to energy efficiency. They calculate the efficiency of the solar water heaters during initial and final tests and compare the efficiencies to those of models currently sold on the market (requiring some additional investigation by students). After comparing efficiencies, students explain how they would further improve their devices. Students learn about the trade-offs between efficiency and cost by calculating the total cost of their devices and evaluating cost per percent efficiency and per degree change of the water.
Students are introduced to the health risks caused by cooking and heating with inefficient cook stoves inside homes, a common practice in rural developing communities. Students simulate the cook stove scenario and use the engineering design process, including iterative trials, to increase warmth inside a building while reducing air quality problems. Students then collect and graph data, and analyze their findings.
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.
Students are introduced to the concept of viscoelasticity and some of the material behaviors of viscoelastic materials, including strain rate dependence, stress relaxation, creep, hysteresis and preconditioning. Viscoelastic material behavior is compared to elastic solids and viscous fluids. Students learn about materials that have viscoelastic behavior along with the importance of engineers understanding viscoelasticity. To best engage the students, conduct the first half of the associated Creepy Silly Putty activity before conducting this lesson.