Ring and Discs Demonstration Kit In Stock Now

Ready, set, go! A ring and disc of equal mass and diameter speed down an inclined plane. Which one wins? Not an easy prediction to make, but the victor will be clear. Results are explained using concepts of inertia, rotational inertia and potential and kinetic energy. Once students understand the results of the first race, they predict the outcome of a race between the ring and two discs—the second disc being larger than the first. Will the disc diameter make a difference?

Concepts: Rotational motion, potential energy, moment of inertia, kinetic energy, Newton’s Law of Motion.

Time Required: 15 minutes

Materials Included:

• 3.5" diameter wood disc,
• 5" diameter wood disc,
• 3.5" diameter plastic ring

Materials Required but not included:

• Balance (at least 1 gram precision)
• Inclined plane such as a wooden board
• Ruler or meter stick
• Wood block or book

See additional file for instructions.

Click here for complete lesson plan.