Pressure and area relationship in fluids

In summary, when considering the relationship between pressure and area in a fluid, it is important to take into account whether the fluid is moving or standing still. In a moving fluid, decreasing the area results in a decrease in pressure due to fewer collisions between molecules. However, in a static fluid, decreasing the area leads to an increase in pressure due to more collisions between molecules. This may seem to contradict mathematical equations, but it aligns with intuitive understanding.
  • #1
David513
1
0
Hoping to clarify something about this...

Is it fair to say that you should consider the relationship between pressure and area as a function of whether a fluid is moving or standing still?

In other words, when a fluid is moving and you decrease the area, the pressure goes down because there is more uniform translational motion in a moving fluid, therefore fewer molecules of the fluid collide with each other.

Meanwhile, when a fluid is standing still and you decrease the area, the pressure goes up because there is more random translation motion in a resting fluid, therefore more molecules of the fluid collide with each other.

This seems to defy P=F/A and Bernoulli's equation but makes sense intuitively... help!
 
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  • #2
In a flowing fluid the total pressure = static pressure + dynamic pressure; so, the total pressure does not change nor does the mass flow change from one cross section to the other smaller one. For a static fluid when the mass does not change but the volume is reduced then there is an a change of total pressure.
 

Related to Pressure and area relationship in fluids

What is the relationship between pressure and area in fluids?

The relationship between pressure and area in fluids is known as Pascal's law, which states that the pressure applied to a confined fluid is transmitted equally in all directions. This means that an increase in pressure will result in a decrease in area, and vice versa.

How does the pressure and area relationship affect the behavior of fluids?

The pressure and area relationship in fluids is essential in understanding how fluids behave. For example, when a force is applied to a small area, it results in a high pressure, which can cause fluids to flow or move in a particular direction. On the other hand, when a force is applied to a larger area, it results in a lower pressure, which can cause fluids to spread out or disperse.

What is the equation for pressure and area in fluids?

The equation for pressure and area in fluids is P = F/A, where P is the pressure, F is the force applied, and A is the area over which the force is applied. This equation is based on the concept of Pascal's law and is used to calculate the pressure at a given point in a fluid.

Does the pressure and area relationship apply to all types of fluids?

Yes, the pressure and area relationship applies to all types of fluids, including liquids and gases. This is because all fluids are subject to the same laws of physics, which govern their behavior. However, the exact values for pressure and area may vary depending on the properties of the fluid, such as density and viscosity.

How is the pressure and area relationship used in practical applications?

The pressure and area relationship is used in a variety of practical applications, such as hydraulic systems, scuba diving, and weather forecasting. It is also essential in understanding how fluids flow through pipes, pumps, and other devices. Additionally, it is used in industries such as aviation, where the principles of fluid dynamics are crucial in designing aircraft wings and engines.

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