Objectives

To demonstrate Bernoulli’s Principle

Materials

• Plastic empty water bottle
• Small piece of paper

Procedure

Turn the plastic bottle on its side. Create a paper ball that sits loosely inside the mouth of the bottle. Place your mouth approximately one inch from the mouth of the bottle. Blow air to attempt to move the paper ball into the bottle. What happens?

Conclusion

The paper ball wiggles before flying OUT of the bottle! You can’t blow air into the bottle because it is already full of air.  However, when you blow, air is moving along the sides of the bottle. When the air blows past the mouth of the bottle, it creates an area of low pressure behind it. This is called the Bernoulli Principle. This area of low pressure is what the paper ball needs to fly out of the bottle’s mouth. Try other small objects and see what happens.