i am in 9th grade and i have a science project on the physics of airplanes do on jan. 9 9th i was wondering if you could give me some sources and information…thanks
For a physics class, the key science to understand was developed by a Dutch physicist named Daniel Bernoulli in the mid 1700’s. It explains why the airfoil shape of the wing causes the air flowing over the top of the wing to move faster than the air flowing over the bottom of the wing resulting in lower pressure on top thereby creating lift. Search on Bernoulli and you will find many references.
Which you’ll learn later on accounts for only some of the lift that makes an airplane fly. And it does not explain why a hand out the window of a moving car creates lift also. But it’s what we’re all taught. **Also **you might learn that starting a sentence with a conjunction is not good.
One word of advice: CHECK your spelling. I don’t know if teachers still take off points for spelling but they should. As an example, the word is spelled “due” and not “do.” There’s also an apostrophe in I’ll (along with a capital “I”).
Just curious as I don’t know the scientific answer myself, but would the lift on the hand in a general sense be the same concept of ground lifting in an earthquake (one plate sliding under another) or water lifting a boat upward in a wave and not utilizing the concept of flight?
In other words, it’s a “mechanical” (lack for a better word) force pushing your hand up based on the angle of your hand rather then Bernoulli effect?
It’s simple. With your hand perfectly horizontal out the car window, air goes evenly both over and under it, keeping it level. Your hand is pretty much the same height all the way across so no special aerodynamics. When you angle the front of your hand upward just slightly, air is allowed underneath, hits the underneath backside of your palm and lifts it. I don’t know what it’s called, maybe the Chittichittibangbang effect. 8)
Part of it is simply the hand deflecting the wind downward, imparting an upward moment. Same thing happens with a wing at high angles of attack. Another force is the Coanda Effect. I can’t do as good a job explaining it as you might be able to find online.
As you know, this is the subject of much debate in aeronautical engineering circles. Some say that it is still the Bernoulli principle at work as the air hitting the leading edge of a slanted hand out the window travels different distances over the top and bottom, while others say that it is a simple ram air effect. In any case, a hand out the window in a poor model of a flying surface because a hand is not changing velocity with respect to the relative wind to the same degree as a wing.
The more meaningful question, which I haven’t seen answered anywhere yet, is how much this ‘ram force’ contributes to lift vs. how much the Bernoulli force does.
From the American Heritage Book of Grammar Usage:
also beginning a sentence. Some people maintain that it is wrong to begin a sentence with also. They are probably in the minority, since there seems no reason to condemn also and not another conjunctive adverb like nevertheless. In an earlier survey, 63 percent of the Usage Panel found the usage acceptable in this example: The warranty covers all power-train components. Also, participating dealers back their work with a free lifetime service guarantee.