To share with the entire class:

• scale (~500-1000 g)

Each group needs:

• stopwatch
• large bottle filled with water (500 ml – 1 L water or soda bottle)
• meter stick
• pole (2-3 cm dowel, ~ ½ m long)
• rope/string to tie bottle to dowel with ½ - 1 m length between
• activity sheet and data table (one per student)