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WHAT HAVE WE SEEN SO FAR?. A brief recap…. FLUIDS. So far, we have looked at fluids and we have seen that fluids exist as both liquid and as air. . We have also seen how a fluid passes around an object. BERNOULLI’S PRINCIPLE.
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WHAT HAVE WE SEEN SO FAR? A brief recap…
FLUIDS So far, we have looked at fluids and we have seen that fluids exist as both liquid and as air. We have also seen how a fluid passes around an object.
BERNOULLI’S PRINCIPLE Bernoulli noticed that pressure exists all around us. In fact, he found that stationary fluids such as air and water exert pressure in all directions.
Bernoulli also discovered that the faster air flows, the less pressure it has.
Now, we are going to look at the force of LIFT and see how it applies to flying objects such as airplanes.
Airplanes stay in the air because of the shape of their wings.
DIRECTION OF AIRPLANE Imagine a wing flying fast through the air
An airfoil is flat on the bottom and curved on the top. TOP BOTTOM
DIRECTION OF AIRPLANE TOP BOTTOM
The air flowing over the curved top of the wing has further to go than the air going under the flat bottom of the wing.
The air flowing over the curved top of the wing has further to go than the air going under the flat bottom of the wing.
The air flowing over the curved top of the wing has further to go than the air going under the flat bottom of the wing.
The air flowing over the curved top of the wing has further to go than the air going under the flat bottom of the wing.
The air flowing over the curved top of the wing has further to go than the air going under the flat bottom of the wing.
The air flowing over the curved top of the wing has further to go than the air going under the flat bottom of the wing.
The air flowing over the curved top of the wing has further to go than the air going under the flat bottom of the wing.
The air flowing over the curved top of the wing has further to go than the air going under the flat bottom of the wing.
The air flowing over the curved top of the wing has further to go than the air going under the flat bottom of the wing.
The air flowing over the curved top of the wing has further to go than the air going under the flat bottom of the wing.
The air flowing over the curved top of the wing has further to go than the air going under the flat bottom of the wing.
The air flowing over the curved top of the wing has further to go than the air going under the flat bottom of the wing.
The air flowing over the curved top of the wing has further to go than the air going under the flat bottom of the wing.
The air flowing over the curved top of the wing has further to go than the air going under the flat bottom of the wing.
The air flowing over the curved top of the wing has further to go than the air going under the flat bottom of the wing.
Predict: How will both air molecules arrive at the tail of the wing at the same time if the molecule on top has a farther distance to travel?
For the two streams of air to reach the back of the wing at the same time, the top stream must travel faster than the bottom. (It has a farther distance to go.)
For the two streams of air to reach the back of the wing at the same time, the top stream must travel faster than the bottom. (It has a farther distance to go.)
For the two streams of air to reach the back of the wing at the same time, the top stream must travel faster than the bottom. (It has a farther distance to go.)
LOW PRESSURE HIGH PRESSURE This fast moving air creates a low pressure area on the top of the wing and a high pressure area on the bottom of the wing. (Bernoulli’s Principle)
LOW PRESSURE HIGH PRESSURE Predict: What is our high pressure air zone going to do? Why?
LOW PRESSURE HIGH PRESSURE Air will move from a high pressure zone to low pressure zone. As it pushes against the wing, lift is created.