Discovery Education
Discovery Education: 3 M Young Scientist Lab: Two Stage Ballon Rocket
Build a multistage rocket from two balloons.
Science Buddies
Science Buddies: Hey Gear Heads! The Physics of Bicycle Gear Ratios
Here's an abstract of a project from Science Buddies that asks you to experiment with bicycle gears and the circumference of the wheel to determine revolutions per minute.
Discovery Education
Discovery Education: Introduction to Physical Science
Introduce students to the ideas of motion and force in this hands-on lesson plan.