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Learn to Make Objects Levitate with the Bernoulli Levitator Principle

Subjects

• Science

Grade

• 9-12

Brief Description

Students suspend an object in the air by blowing down on it.

Objectives

Students explore the Bernoulli Principle.

Keywords

Bernoulli Principle, air pressure

Materials Needed

large wooden or plastic thread spools, index cards trimmed to 3 by 3 inches, pushpins, 2-inch sections of drinking straws (optional)

Lesson Plan

• Provide each student or group of students with a spool, an index card, and a pushpin. If students are working in groups, also provide each student with a 2-inch piece of a drinking straw.
• Have students hold a card against the bottom of a spool with the pushpin sticking into the spool's hole and blow strongly through the hole in the top of the spool as they let go of the card. (If the card falls at first, experiment with different sized cards or spools until the card hangs suspended beneath the spool.)
• Discuss with students why the card could be suspended by blowing down on it. (When a person blows into the spool, the air hits the card and accelerates outward. As the air accelerates, its pressure drops. The air rushing between the spool and the card exerts less pressure on the card than does the still air underneath the card. The still air pushes the card toward the spool and holds the card up against gravity.)

Note: The entire experiment, including explanations and a more involved version, can be found at the Bernoulli Levitator site.

Assessment Evaluate students on their participation in a discussion following the experiment.

Lesson Plan Source

Science Snacks Online from The Exploratorium

National Standards

Science:
NS.9-12.2