Low pressures at high velocities

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In summary, the pressure decreases as the velocity increases due to the Bernoulli's effect or principle, which is based on the conservation of energy. This is because as the speed of the fluid increases, the particles hit the edge of the medium less, requiring less pressure to accelerate the fluid. This is explained by Newton's Second Law, F = ma, where a higher pressure is needed upstream to accelerate the fluid.
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Jewish_Vulcan
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Why does pressure decrease as velocity increases, I think it is because pressure is defined as particles hitting the edge of the medium so when velocity increases the particles hit the edge of the medium less but how?
 
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It is called the Bernoulli's effect or principle and is to do with the conservation of energy. If speed increases then pressure has to decrease so the total energy remains the same.
 
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Jewish_Vulcan said:
Why does pressure decrease as velocity increases, I think it is because pressure is defined as particles hitting the edge of the medium so when velocity increases the particles hit the edge of the medium less but how?
This is an F = ma (Newton's Second Law) kind of thing. If the velocity is increasing, then the fluid is being accelerated. In order to accelerate the fluid, you need to apply a higher pressure (force per unit area) upstream than downstream.

Chet
 
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Chestermiller said:
This is an F = ma (Newton's Second Law) kind of thing. If the velocity is increasing, then the fluid is being accelerated. In order to accelerate the fluid, you need to apply a higher pressure (force per unit area) upstream than downstream.

Chet
ok thank you, I was thinking that but could not really visualize it, I guess sometimes you just have to trust equations even if they do not make sense...
 

1. What causes low pressures at high velocities?

Low pressures at high velocities are caused by the Bernoulli principle, which states that as the speed of a fluid increases, its pressure decreases.

2. How does low pressure at high velocities affect objects?

Low pressure at high velocities can create lift, which is the force that allows airplanes to fly. It can also cause drag, which is the resistance force that opposes the motion of an object through a fluid.

3. How is low pressure at high velocities measured?

Low pressure at high velocities is typically measured using a device called a manometer, which measures the difference in pressure between two points in a fluid flow.

4. Can low pressure at high velocities be dangerous?

In certain situations, low pressure at high velocities can be dangerous. For example, in a tornado, low pressure at high velocities can cause objects to be lifted and carried away. It can also cause structural damage to buildings.

5. How can low pressure at high velocities be controlled?

Low pressure at high velocities can be controlled through various methods such as increasing the fluid density, decreasing the velocity, or using devices such as spoilers or flaps to manipulate the flow of the fluid. In aerodynamics, airfoils are also used to create lift and reduce drag in order to control low pressure at high velocities.

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