The lesson begins with a demonstration introducing students to the force between two current carrying loops, comparing the attraction and repulsion between the loops to that between two magnets. After formal lecture on Ampere's law, students begin to use the concepts to calculate the magnetic field around a loop. This is applied to determine the magnetic field of a toroid, imagining a toroid as a looped solenoid.

An example of simplifying a seemingly complicated resistor circuit. Created by Willy McAllister.

Students prepare for the associated activity in which they investigate acceleration by collecting acceleration vs. time data using the accelerometer of a sliding Android device. Based on the experimental set-up for the activity, students form hypotheses about the acceleration of the device. Students will investigate how the force on the device changes according to Newton's Second Law. Different types of acceleration, including average, instantaneous and constant acceleration, are introduced. Acceleration and force is described mathematically and in terms of processes and applications.

Students investigate the motion of a simple pendulum through direct observation and data collection using Android® devices. First, student groups create pendulums that hang from the classroom ceiling, using Android smartphones or tablets as the bobs, taking advantage of their built-in accelerometers. With the Android devices loaded with the (provided) AccelDataCapture app, groups explore the periodic motion of the pendulums, changing variables (amplitude, mass, length) to see what happens, by visual observation and via the app-generated graphs. Then teams conduct formal experiments to alter one variable while keeping all other parameters constant, performing numerous trials, identifying independent/dependent variables, collecting data and using the simple pendulum equation. Through these experiments, students investigate how pendulums move and the changing forces they experience, better understanding the relationship between a pendulum's motion and its amplitude, length and mass. They analyze the data, either on paper or by importing into a spreadsheet application. As an extension, students may also develop their own algorithms in a provided App Inventor framework in order to automatically note the time of each period.

Introducing angular momentum conceptually starting from linear momentum. Also covers some real-life examples. Created by Sal Khan.

David explains the meaning of angular displacement, angular velocity, and angular acceleration. Created by David SantoPietro.

In uniform circular motion, angular velocity (𝒘) is a vector quantity and is equal to the angular displacement (Δ𝚹, a vector quantity) divided by the change in time (Δ𝐭). Speed is equal to the arc length traveled (S) divided by the change in time (Δ𝐭), which is also equal to |𝒘|R. And arc length (S) is equal to the absolute value of the angular displacement (|Δ𝚹|) times the radius (R).

In this demonstration, amaze learners by performing simple tricks using mirrors. These tricks take advantage of how a mirror can reflect your right side so it appears to be your left side. To make the effect more dramatic, cover the mirror with a cloth, climb onto the table, straddle the mirror, and then drop the cloth as you appear to "take off." This resource contains information about how this trick was applied during the making of the movie "Star Wars."

In this simple exploration, a coiled phone cord slows the motion of a wave so you can see how a single pulse travels and what happens when two traveling wave pulses meet in the middle.

Antimatter, the charge reversed equivalent of matter, has captured the imaginations of science fiction fans for years as a perfectly efficient form of energy. While normal matter consists of atoms with negatively charged electrons orbiting positively charged nuclei, antimatter consists of positively charged positrons orbiting negatively charged anti-nuclei. When antimatter and matter meet, both substances are annihilated, creating massive amounts of energy. Instances in which antimatter is portrayed in science fiction stories (such as Star Trek) are examined, including their purposes (fuel source, weapons, alternate universes) and properties. Students compare and contrast matter and antimatter, learn how antimatter can be used as a form of energy, and consider potential engineering applications for antimatter.

Sal applies Newton's first law the answer some true/false statements about why objects move (or not). Created by Sal Khan.

Students are introduced to Pascal's law, Archimedes' principle and Bernoulli's principle. Fundamental definitions, equations, practice problems and engineering applications are supplied. A PowerPoint® presentation, practice problems and grading rubric are provided.

In this video, David explains how an atom can absorb and emit photons with particular values of energy and how to determine the allowed values.

What starts out as a cascade of well-mixed granular materials sorts itself into alternating layers of salt and sand.

Sal solves a word problem to find average velocity and speed of an object in one-dimension.

This webpage from Exploratorium provides an activity that demonstrates the Bernoulli principle with readily available materials. In this activity a table tennis ball is levitated in a stream of air from a vacuum cleaner. The site provides an explanation of what happens, asks questions about the activity, and also describes applications to flight. This activity is part of Exploratorium's Science Snacks series.

In this quick and simple activity, learners explore how the distribution of the mass of an object determines the position of its center of gravity, its angular momentum, and your ability to balance it. Learners discover it is easier to balance a wooden dowel on the tip of their fingers when a lump of clay is near the top of the stick. Use this activity to introduce learners to rotational inertia.

David explains how a mass can have angular momentum even if it is traveling along a straight line. Then David shows how to solve the conservation of angular momentum problem where a ball hits a rod which can rotate. Created by David SantoPietro.

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.