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Bernoulli's Principle - Soda Can Dance (Rena Benor)

Author


Rena Benor       

Principles Illustrated

1.      Bernoulli Effect

2.   Airflow creates a low pressure

3.   Low pressure creates lift.

 
Standards
Investigation and Experimentation 8th grade
. Scientific progress is made by asking meaningful questions and conducting careful investigations. As a basis for understanding this concept and addressing the content in the other three strands, students should develop their own questions and perform investigations.
 Students will: 
  a. Develop a hypothesis. b. Select and use appropriate tools and technology to perform tests, collect data, and display data e. Recognize whether evidence is consistent with a proposed explanation.

Gases and Their Properties     Grade Nine through Twelve

4 c. Students know how to apply the gas laws to relations between the pressure, temperature, and volume of any amount of an ideal gas or any mixture of ideal gases.
h. Students know how to solve problems by using the ideal gas law in the form PV=NkT.

Questioning Script: 

Prior knowledge & experience: Air pushes objects apart

Root question:

What do you think happened to bring the two cans together? What could have caused a decrease in air pressure between the cans?
Target response:  When a ball or other curved object is placed in an air stream, the air will increase its speed as it moves around the outside of the can. This happens because the air has to travel a further distance to get around the can and meet back up on the other side of the can.

The connection between air speed and air pressure is at the center of Bernoulli's Theorem. When the air increases its speed as it moves around the ball, the air pressure around the ball also drops. In the places where the air moves the fastest, the air pressure is also the lowest.

The low air pressure around the cans pull them together. When a student blows hard on the can, you increase the speed of the air around it. This also causes the air pressure to decrease, which then pulls the cans even closer.


Common Misconceptions:

Most students will predict that the cans will be blown apart.

Youtube:   http://youtu.be/olVJzVadiFs 

                  http://youtu.be/olVJzVadiFs

                   http://youtu.be/P-xNXrELCmU

References

www.eHow.com

How to explain Bernoulli's principle to kids

 

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