What is Bernoulli's principle? Use Bernoulli's principle to explain how one of the following works: an airfoil, a curve ball, the wind blowing the roof off a house.
As the pressure goes down the velocity goes up to keep the total energy the same.
1. airfoil, you need to know one more thing, the "Kutta condition" which says that the air flows smoothly off the rear of the wing rather than sneaking around the sharp edge and forming a stagnation point on the upper surface. That means the path is longer around the front and down the top, and therefore the air moves faster over the top of the wing. Low pressure on the top, higher on the bottom ---> force up, fly.
2. curve ball, he spinning ball retrds the flow on one side and speeds it up on the other, pressure is lower on the fast side as you know now so there is a side force.
3. air flow fast over the roof, stops at the walls and windows and doors and inside and underneath. Pressure high under, low over -- Boom!
Bernoulli's principle states that as the speed of a fluid (liquid or gas) increases, its pressure decreases, and vice versa, when the speed decreases, the pressure increases. This principle is based on the conservation of energy of a fluid flowing through a tube or around an object.
Now, let's apply Bernoulli's principle to explain how an airfoil, like an airplane wing, works. An airfoil is designed to generate lift, which is the force that allows an airplane to fly. On the upper side of the airfoil, the air flows faster than on the lower side due to its shape. According to Bernoulli's principle, as the air flows faster on the top surface, it experiences lower pressure compared to the slower-moving air on the bottom surface. This pressure difference creates a net upward force, which is the lift that enables the airplane to stay airborne.
Next, let's apply Bernoulli's principle to explain how a curve ball in sports, like baseball or softball, works. When a pitcher throws a curve ball, they impart spin on the ball, causing the air around it to flow differently on each side. As the ball spins, it creates a pressure difference between the top and bottom surfaces, generating an asymmetric airflow around the ball. According to Bernoulli's principle, the air moving faster on one side of the ball experiences lower pressure, causing the ball to curve in the direction of lower pressure. This phenomenon is known as the Magnus effect and is responsible for the curveball's movement.
Lastly, let's use Bernoulli's principle to explain how strong winds can blow the roof off a house. When there is a strong wind blowing over a house, it creates a pressure difference between the outside and inside of the house. The wind passing over the roof creates low pressure on the upper side of the roof, while the air inside the house remains at a relatively higher pressure. According to Bernoulli's principle, this pressure difference can result in an upward force that can lift the roof off. Additionally, if the wind flow on the sides of the house is obstructed, it can cause an increase in air velocity over the roof, further lowering the pressure and increasing the lifting force.
Bernoulli's principle states that as the speed of a fluid (liquid or gas) increases, its pressure decreases. Conversely, as the speed of a fluid decreases, its pressure increases. This principle helps explain the behavior of airflow around objects like airfoils, the curve of a baseball, and the force of wind on a roof.
1. Airfoil: An airfoil is a streamlined shape, often used in aircraft wings. As air flows over an airfoil, it splits into two paths: over the curved upper surface and below the flatter lower surface. According to Bernoulli's principle, the air moving over the curved upper surface has to travel a longer distance in the same amount of time compared to the air below, which moves along the flatter surface. Therefore, the air above the airfoil must accelerate and create a lower pressure than the air below. This difference in pressure generates lift, allowing an aircraft to stay aloft.
2. Curve ball: When a pitcher throws a curveball in baseball, the ball experiences airflow that creates a pressure differential, causing the ball to curve. The pitcher applies a spinning motion to the ball, creating a difference in airflow on either side due to Bernoulli's principle. The air moves faster relative to the side spinning in the same direction it is moving, resulting in lower pressure. The side spinning against the direction of motion has slower airflow, thus experiencing higher pressure. The pressure difference pushes the ball in the direction of lower pressure, causing the curveball trajectory.
3. Wind blowing the roof off a house: Wind blowing against a roof exerts a force due to differences in air pressure. Bernoulli's principle explains that when wind flows across a roof, the air on the wind-facing side speeds up, creating lower pressure. In contrast, the air on the leeward side of the roof moves more slowly, generating higher pressure. The difference in pressure creates an upward force that can lift or remove the roof. This phenomenon is more pronounced when wind speeds increase, causing a significant pressure differential between the two sides of the roof.
In summary, Bernoulli's principle helps us understand how the speed of a fluid affects its pressure, which explains many phenomena related to airflow, such as the lift generated by airfoils, the curve of a baseball, and the forces of wind on structures.