This site details how simple machines create a mechanical advantage for humans. Levers, theoretical mechanical advantage, actual mechanical advantage, and pulley systems are discussed.

This lesson is for 9th grade physical science students. It begins with an inquiry-based lesson using a projectile motion computer simulation. It culminates with students building a catapult; applying and connecting science knowledge from...

A simple activity that investigates the basic principles behind static electricity. The activity is in lesson plan format that meets NSES standards.

In this lesson summary review and remind yourself of the key terms and calculations used in measuring unemployment, the labor force, the unemployment rate, the labor force participation rate, and the natural rate of unemployment. Topics...

Animation of the single-block "Earthquake Machine" model shows how "Forces, Faults, and Friction" interact. [0:16]