# Another aerodynamic / lift question

#### ozziecat35

##### 4 out of 5 great lakes prefer Michigan.
Backstory: my 5 year old daughter is becoming more and more fascinated with airplanes, and my wife home schools her, so we have a perfect opportunity to introduce some basic "how does an airplane fly" science into her curriculum. As I understand it, the FAA prefers the Bernoulli & Newton's 3rd law explanations to be taught to students. Obviously there are more complex physics involved then just Bernoulli and Newton, but that's over my head too. I seem to recall a thread a while back where someone linked to a NASA article explaining lift, which was very technical...that being said, as I was doing some online googling to find better ways to explain to my daughter how an airplane flies, I came across this:

which is basically a very basic Bernoulli explanation. That's fine, but also goes against what I thought was the group thought that comes down to the, "Well, Bernoulli and Newton aren't a wrong way to teach it, but there's more to the story," idea. At what does NASA decide someone can learn the "truth" and tell them there's more to the B&N explanation.

If you've followed my ramblings so far, congratulations, I'll try and get to the point. I'm about to take my CFI checkride, and I want to make sure that Bernoulli / Newton is still the correct way to teach lift. (Also if anyone has cool ideas for a VERY smart 5 year old interested in the subject, my wife and I are all ears!).

#### desertdog71

##### Girthy Member
hang two tennis balls side by side on strings with a couple inches between them. Blow up between them and they will come together. Basic Bernoulli/Venturi demonstration.

#### ozziecat35

##### 4 out of 5 great lakes prefer Michigan.
Awesome idea Van. Thanks.

#### desertdog71

##### Girthy Member
You can also hold the corners of a piece of paper and bow it slightly, hold it to your mouth and blow across the top. The paper will lift. Hard to describe without showing you, but it does the job.

#### matthew

##### Well-Known Member
You can also hold the corners of a piece of paper and bow it slightly, hold it to your mouth and blow across the top. The paper will lift. Hard to describe without showing you, but it does the job.

#### SrFnFly227

##### Well-Known Member
Get a full cup of water and two straws. Put one straw in the water and hold the other at about 90 degrees to the top of the first. Blow in to the straw you're holding and water will come up the straw that's in the cup and spray out in a mist.

Edit: found a video

#### Mike Massimini

##### Well-Known Member
ozziecat35 said:
At what does NASA decide someone can learn the "truth" and tell them there's more to the B&N explanation ... ?
Well, never, because there ain't a whole lot more to it, as far as lift generation. Bernoulli is basically a result of Newton, although the former is used, at least partly, for calculations - at least 'way back when I was still in school. The principles are quite simple; it's the calculations that get involved.