How does a lens form an image? See how light rays are refracted by a lens. Watch how the image changes when you adjust the focal length of the lens, move the object, move the lens, or move the screen.

This tool allows you to learn about various geometric solids and their properties. You can manipulate each solid, seeing it from every angle. You can also color each shape to explore the number of faces, edges, and vertices. With that information, you are challenged to investigate the following question: For any polyhedron, what is the relationship between the number of faces, vertices, and edges?

This activity is a lab where the students try to make a lightbulb light up using two wires, a battery and a lightbulb.

The activity follows a progression that examines the CO2 content of various gases, explores the changes in the atmospheric levels of CO2 from 1958 to 2000 from the Mauna Loa Keeling curve, and the relationship between CO2 and temperature over the past 160,000 years. This provides a foundation for examining individuals' input of CO2 to the atmosphere and how to reduce it.

This video segment adapted from NOVA/FRONTLINE examines the greenhouse effect, its role in keeping Earth habitable, and the industrial changes that have led to an increase in the planet's average temperature.

Students use hot glue gun sticks to learn about the forces of tension, compression and torsion.

Students explore the effects of regional geology on bridge foundation, including the variety of soil conditions found beneath foundations. They learn about shallow and deep foundations, as well as the concepts of bearing pressure and settlement.

This lesson introduces the MRI Safety Grand Challenge question. Students are asked to write journal responses to the question and brainstorm what information they will need to answer the question. The ideas are shared with the class and recorded. Students then watch a video interview with a real life researcher to gain a professional perspective on MRI safety and brainstorm any additional ideas. The associated activity provides students the opportunity to visualize magnetic fields.

Students are introduced to the Robotics Peripheral Vision Grand Challenge question. They are asked to write journal responses to the question and brainstorm what information they require to answer the question. Their ideas are shared with the class and recorded. Then, students share their ideas with each other and brainstorm any additional ideas. Next, students draw a basis for the average peripheral vision of humans and then compare that range to the range of two different focal lengths in a camera. Through the associated activity provides, students see the differences between human and computer vision.

Graphical Just-in-Time-Teaching questions for use before classes in which students explore position, velocity and acceleration graphs.

In this demonstration students are given a position, velocity or acceleration graph showing the motion of an object. They are asked to write a short description of the motion, and make predictions by completing the remaining two graphs.

In this lesson designed to enhance literacy skills, students learn how to read and interpret a distance–time graph.

Students learn about water poverty and how water engineers can develop appropriate solutions to a problem that is plaguing nearly a sixth of the world's population. Students follow the engineering design process to design a gravity-fed water system. They choose between different system parameters such as pipe sizes, elevation differentials between entry and exit pipes, pipe lengths and tube locations to find a design that provides the maximum flow and minimum water turbidity (cloudiness) at the point of use. In this activity, students play the role of water engineers by designing and building model gravity-fed water systems, learning the key elements necessary for viable projects that help improve the lives people in developing communities.

Visualize the gravitational force that two objects exert on each other. Change properties of the objects in order to see how it changes the gravity force.

Visualize the gravitational force that two objects exert on each other. Change properties of the objects in order to see how it changes the gravity force.

Move the sun, earth, moon and space station to see how it affects their gravitational forces and orbital paths. Visualize the sizes and distances between different heavenly bodies, and turn off gravity to see what would happen without it!

Move the sun, earth, moon and space station to see how it affects their gravitational forces and orbital paths. Visualize the sizes and distances between different heavenly bodies, and turn off gravity to see what would happen without it!

This activity is a field lab where students use a half gallon milk/juice carton containing two raw eggs and "other" materials to design an internal protective structure that will prevent the eggs from breaking from a 50 foot drop off a roof top.

This is a debate-style learning activity in which student teams learn about energy sources and are then assigned to represent the different energy sources. Working cooperatively, students develop arguments on the pros and cons of their source over the others.