Each group needs:

• 1-3 objects, such as a block, toy car, etc. (Note: The cart developed in the hands-on activity in Lesson 3 of this unit is ideal as an object for this activity. The number of objects tested depends on the time available.)
• One wooden board (approximately 40 cm x 20 cm)
• Text books (4 or 5 for stacking)
• Pencil
• Protractor
• Let it Slide! Worksheet
• Spring scale (one per team if available, or share a few among the class; available from science supply catalogs, stores or websites)