Concepts

Newton's first law

Overview

A small ball bearing moves in a circle inside a broken ring, eventually reaching the break and continuing in a straight line towards one of several miniature bowling pins.

Details

Equipment

• [1] Broken ring
• [1] Ball bearing
• [5] Miniature bowling pin
• [1] Level
• [1] Set of shims
• [1] Document camera or overhead projector
• [1] Water-washable marker

Classroom Assembly

1. Place the broken ring apparatus under a document camera or on a projector.
2. Use the shims and thumbscrews to level the apparatus.
3. Test the levelling by dropping a ball onto the Plexiglas.
4. Remove the ring cover.
5. Launch the ring a couple of times to see where it ends up.
6. Place one of the bowling pins there. Place the other pins as possible other choices in a multiple choice question. Label the pins with the water-washable marker, if desired.

Important Notes

• Try to be consistent in how you push the ball. The motion of the ball depends slightly on the speed at which you propel the ball through the ring, possibly due to the spin it picks up in the process.
  

Script

1. Make students guess which pin will be hit.
2. Launch the ball.

Additional Resources