1

Chris AbbandonatoEDUC 5863 Discrepant Event Presentation

The Floating Ping-Pong Ball

The Science Concept: Bernoulli’s Principle stating that the faster the flow ofair, the lower the pressure.

Grade Level: Grade 6

Science Unit: Physical Science: Flight- Lift and Bernoulli’s PrincipleSection. (Already learned about drag, gravity and afterwards thrust)

Curriculum Outcome: Students will be expected to identify situations,which involve Bernoulli’s Principle. Students should explore many situationsinvolving Bernoulli’ s principle, and give explanations as to why objects moveas the do using the principle.

Target Science Misconception: Students would assume that the ping-pongball would blow away and fall right down.

Materials: A hair dryer and a ping-pong ball. Also a funnel and plastic tubingcould be used for props leading to the experiment.

2

Procedure:• Plug in the hair dryer and set to high speed and cool air• Turn on the hair dryer• Ask the students to predict what will happen to the ping-pong ball as

it is placed in the air flow• Place the ping-pong ball in front of the air flow• Move different directions with the hair dryer• Observe the predictions

Leading questions/prompts before the experiment:• What’s the best way to send a ping-pong ball up in the air?

Shoot the ping-pong ball out of a funnel and observe Throw up the ping-pong ball and observe what happens Shoot the ping-pong ball using plastic wire Blow the ping-pong ball off the table using the blow dryer and

observe what happens (different direction: straight ahead andon an angle)

Throw up the ping-pong ball and blow it as it is in the air

3

Leading questions/prompts after the experiment:• Will we be able to do the same experiment with other round objects?• What property of the round object is critical for the ping-pong ball to

stay afloat?• What does the blowing do to the movement of the air molecules?• How does pressure of flowing air compare to that of stationary air?• What stopped the ping-pong ball from shooting up? (Gravity exerts a

greater force on the ping-pong ball than air pressure)• Why does the ping-pong ball stay floating in the air stream and follows

the air stream in different directions?• Is there a way that the ping-pong ball can fall out of the airflow?

Scientific Solution:• The pressure inside the flow of air given off by the hair dryer is lower

than the pressure from the air that is circulating around it (stationaryair, air not moving fast) .In other words fast moving air exerts lesspressure than slow moving air, describing Bernoulli’s Principle. Thecirculating air is giving off a higher pressure, which allows the ping-pong ball to stay in the area of low pressure. When tilting the hairdryer, the circulating air pressure is still high enough to keep the ping-pong ball floating in the air, unless you tilt the hair dryer to much inthe horizontal position, then the force of gravity takes over and theping-pong ball will fall.

Alternative approaches and other related experiments:• Do the same experiment using a balloon or a beach ball.• Do a similar experiment involving floating a ping-pong ball in the air,

but not quite the same. The experiment is called the funnel and theball. The idea is to pick up the ping-pong ball using Bernoulli’sPrinciple of the faster the flow of air, the lower the pressure byblowing air throw the funnel.

• Curriculum suggestion: Hang two ping-pong balls 6-10cm apart andthen blow between them and observe what happens.

4

Real-Life Examples:• Shower Curtains

When you turn on the shower, the showerhead releases water ina downward motion, pushing air with it. Therefore the movingair in the shower than creates a lower pressure and the showercurtain gets sucked into the shower.

• Hair floating in the Car When you’re driving and your car window is open, your hair is

being sucked out of the window. Food for thought, Bernoulli’sPrinciple in action again.

A Definition of Pressure:• Pressure is developed when a force is applied on an object.

References:• New Brunswick Grade 6 Curriculum Guide• Everything Done by Mr. G, Go With the Flow Episode 23 Science

video:http://www.youtube.com/watch?v=cm1EcccXnQk&playnext=1&list=PLC3443C05A2A80E68

• How to float a ping-pong ball in the air Science video:http://www.videojug.com/film/how-to-float-a-ping-pong-ball-in-the-air

• Liem Tik, Invitations to Science Inquiry 2nd edition.• http://scifun.chem.wisc.edu/homeexpts/bernoulli.htm