Play with one or two pendulums and discover how the period of a simple pendulum depends on the length of the string, the mass of the pendulum bob, and the amplitude of the swing. It's easy to measure the period using the photogate timer. You can vary friction and the strength of gravity. Use the pendulum to find the value of g on planet X. Notice the anharmonic behavior at large amplitude.

The CK-12 21st Century Physics FlexBook is a collaborative effort of the Secretaries of Education and Technology and the Department of Education that seeks to elevate the quality of physics instruction across the Commonwealth of Virginia.

This video lesson explores Newton's Third Law of Motion through examination of several real world examples of this law in action, including that of a donkey cart - a site common in the streets of Pakistan. Students will understand that forces act on objects even if the objects appear to be static and that certain conditions - gravity in particular - affect how two objects interact. The time needed to complete this lesson is approximately 50-60 minutes, and students should be familiar with basic mechanics such as Newton's laws, levers, etc. The materials required are a couple of spring balances, a meter rule, tape, pencil, two desks, and some lab weights (few grams each). The types of in-class activities for between the video breaks include active discussions and participation by students in activities related to the Third Law.

Blast a Buick out of a cannon! Learn about projectile motion by firing various objects. Set the angle, initial speed, and mass. Add air resistance. Make a game out of this simulation by trying to hit a target.

Explore forces and motion as you push household objects up and down a ramp. Lower and raise the ramp to see how the angle of inclination affects the parallel forces. Graphs show forces, energy and work.

As relief organizations drop supplies in remote areas of need, students will design a device to protect an egg when dropped from a specific height.