Each group needs:

• 1-2 ft (30-60 cm) strips each of four different materials for "runways," such as wood, metal, glass, plastic wrap, wax paper, etc. (let your imagination guide you)
• 1-2 ft (30-60 cm) strips of scrap cardboard or plastic, on which to wrap non-rigid racetrack materials
• something to elevate one end of the material strips (such as a shoebox or a wall)
• several sticks of modeling clay, to attach the strips to the elevated support
• several drops of water
• metric ruler
• pen or marker
• scissors
• tape
• stopwatch
• eye dropper (or more eyedroppers per team if you want to race drops simultaneously)
• (optional) paper towels, for wiping off tracks and for clean-up
• (optional) food coloring