Bernoullis Principle Bernoullis Principle states as the speed

Bernoulli’s Principle

Bernoulli’s Principle states: as the speed of a fluid increases, its internal pressure decreases. S , P

Airplane wings Because of the wing’s front curve, the air that goes over the top of the wing speeds up. This means there is less pressure over the wing. There is normal air pressure below. As the pressure below is higher, it pushes the wing up. Plane’s direction

Spoilers on cars and boats An upside-down wing called a spoiler keeps a vehicle on the ground by supplying a downward force to the rear end of the car.

Applying Bernoulli’s Principle also helps explain why sailboats move so fast. For the sail shown, the air is moving faster on the right side and therefore has a lower pressure.

Applying Bernoulli’s Principle Curveballs can be explained by Bernoulli’s Principle as well. As the ball spins, air on one side moves faster than air on the other side.

A tornado can lift the roof off a house. The difference in pressure above and below the roof can be as much as 20 tons on a 1, 000 sq ft roof – easily enough to take the roof off.

Then the wind blowing under the roof equalizes the pressure below and above. With no lifting force, it crashes down. In the brief time the roof is suspended, entering winds can blow the walls outward, so it looks like the house exploded.

Applying Bernoulli’s Principle Why were we told to open the windows during tornado drills in school? http: //www. youtube. com/watch? v=Guwx. Gj. XRCY&feature=related

Four Forces on Flight

Weight is the force of gravity acting on the mass of the airplane or bird.

Drag is a form of air resistance or friction. Too much drag would slow down a plane or bird so much it couldn’t fly.

Streamlining Engineers design cars and airplanes that reduce drag, so it doesn’t take so much power to move them, and therefore fuel to make them go.

Lift This is the upward force explained by Bernoulli’s Principle. In normal flight, it is equal to the weight of the airplane.

Thrust This is the forward motion supplied by the muscles of a bird, or engine or jet that pushes a plane forward.