Curated OER
Computing the Net Force
Adorable little stick figures push and pull a cart of blocks to explain the push and pull of forces. Future physicists then define force and identify it in different situations on the instructional activity that follows. Concepts covered...
PBS
Pbs Learning Media: To Survive at High Velocity
This video segment adapted from NOVA looks at speed, velocity, and centripetal force on the racetrack. [6:28]
Wolfram Research
Wolfram Math World: Line Segment
This site contains a definition of a line segment. Includes a graphic and links to related sites.