Atmospheric Pressure
Inverted Glass & Water Demonstration
This interactive experiment demonstrates how atmospheric pressure can keep water in an inverted glass when covered with a card. Follow the steps below to see physics in action!
The Science Behind Atmospheric Pressure
What's Happening:
When you invert the glass with the card covering it, two forces are at work:
- Downward force from the weight of the water
- Upward force from atmospheric pressure
Key Concepts:
Atmospheric pressure (about 101,325 Pascals at sea level) is the force exerted by the weight of air above us. In this experiment:
- The card prevents air from entering the glass, creating a partial vacuum
- Atmospheric pressure pushes up on the card with enough force to counteract the water's weight
- This creates equilibrium where the water remains suspended
