PIRA: 6A44.00

Lab Equipment

  • Large plexiglass tank filled with water
  • 200mL or 500mL flask
  • yellow marbles
  • rubber stopper


  1. Place the flask with the marbles into the tank.
  2. Rotate the flask until the rubber stopper is facing the observers (marbles disappear: position 1)
  3. Rotate the flask until marbles reappear
  4. Remove the stopper from the flask and fill with water. Then replace stopper and rotate the flask to position 1. Notice marbles are still visible.