We are huge fans of Bernoulli. This Instructable is perfect for showing our enthusiasm.
Here is a great way to demonstrate Bernoulli's Principal. Bernoulli's Principal states that an increase in velocity of moving fluids is accompanied by a decrease in the fluid's pressure.
The moving air around the ball decreases the pressure directly around the ball but increases the pressure of the air that is in the room relatively speaking. So the air in the room applies pressure on all sides of the ball keeping it in place.
A rounder ball then ours will work better.
How is this used in the classroom? This is just one small step toward a giant leap. We have used this with our middle school students as part of our Flight and Rockets Unit. We also use this with our camps we do over the summer. After discussing Icarus and Daedalus, one of the earliest mentions of humans and flight, we discus the Chinese kites that were used thousands of years ago. This leads us to building kites, launching hot air balloons, and several hands on Bernoulli's Principle activities such as this one. All these activities are working toward Newton and rockets.
How else can this particular instructable be used? Much discussion can be done on air pressure and weather. Much like the air around the ball, Earth has moving air with high and low areas of pressure. The areas of high pressure are moving toward areas of low pressure, bringing us weather fronts.
Step 1: Materials
-A High Velocity Fan
-Light Round Balls (beach ball works well)
-Rounder and lighter the better
Step 2: Fan Up
Start with the fan facing up. Use only appropriate style fan. Placing a fan directly on the floor can be dangerous.
Step 3: Get Ready
Start the fan on high. Hold the ball over the upper facing fan and gently let go. This may take a few tries but ones you get the feel, it will get easier.
Step 4: Floating
Once in the stream of air the ball will float in place. The moving air around the ball has less pressure but the air in the room increases in pressure pushing the ball equally in all directions, keeping it in place.
Step 5: Change the Angle
We slowly moved the fan's degree of angle to see if the ball would continue to float without the fan directly under it. The ball did float without the fan being directly under it! It looks like magic.
Step 6: Try Something Else
Change the variables to investigate the changes.
Try different size beach balls. Try heavier then lighter ones. Try oddly shaped items like balloons.
Step 7: The Small Ball
The small ball in action. We have done this activity for years and found that the more round your ball is the better. Our small ball was not so round and kept falling off after several seconds.
Step 8: Two? Will That Work?
How about trying two balls. Try two that are the same size and then try two that are different sizes.
Step 9: Two Is Crazy
Two the same size is cool and works well. Two of different sizes gets a little crazy.
This can also lead to a whole conversation on Newton and his laws. The ball with the more mass will knock the smaller ball out of the stream of air and on to the floor.
Science is all around us and is so much fun!
Step 10: More Bernoulli
This is an entry in the
Classroom Science Contest