What happens when you invert a cup underwater and try to raise it above the water line? The water remains in the cup! This is one of those scientific conundrums that must be experienced firsthand. What keeps the water in the cup? How big can the cup be? Does the height or the width matter more? This activity helps kids build their mental model of air and water pressures.
Use this to learn and reinforce answers to questions such as:
❑ How can an inverted cup of water remain full as it's pulled upward?
❑ How tall does a simple liquid barometer need to be?
❑ How does a drinking straw work?
Once students work through the activity, they can capture their observations using the included Lab Notes or probing questions included in the instructions.
Concepts Addressed
♦ Air's pressure pushes it into every conceivable space
♦ It's the weight of air (or water) above you that causes pressure
Answer Keys and Teacher Notes address most questions and issues that might arise in this study—you shouldn’t have to do any outside research unless you want to.
Materials Needed Nonconsummables: Assorted plastic cups and bottles (transparent or translucent); bin for water; old towels for cleanup.
Prep Time Collect materials (no consumables)
Teaching Time About 20 mins depending on accompanying writing assignment.
Student Sheets Scaffolded writing prompts & lab reporting
