Leak point pressures: how useful are they?

The concept of pressure at a point in a fluid establishes that pressure within a fluid is uniform in all directions at a specific location. This uniformity occurs because fluid molecules exert force evenly across any point due to their random motion and continuous collisions within the fluid. Pressure at a point is determined by the surrounding fluid molecules and is influenced by factors like depth and density, rather than by shape or orientation.
In a fluid at rest, pressure acts equally in...

The pV diagram, which is a graph of pressure versus volume of the gas under study, is helpful in describing certain aspects of the substance. When the substance behaves like an ideal gas, the ideal gas equation describes the relationship between its pressure and volume. On a pV diagram, it is common to plot an isotherm, which is a curve showing p as a function of V with the number of molecules and the temperature fixed. Then, for an ideal gas, the product of the pressure of the gas and its...

In mechanical engineering, fluid pressure plays a critical role in designing systems that utilize liquid flow, such as hydraulic systems, pumps, and valves. When designing these systems, engineers must ensure they can withstand the forces created by fluid pressure to avoid damage or failure.
According to Pascal's law, a fluid at rest will generate equal pressure in all directions. This pressure is measured as a force per unit area, and its magnitude depends on the fluid's specific...

Most pressure gauges, like those on scuba tanks, are calibrated to read zero at atmospheric pressure. Readings from such gauges are called the gauge pressure, which is the pressure relative to atmospheric pressure. When the pressure inside the tank exceeds atmospheric pressure, the gauge reports a positive value. Some gauges are designed to measure negative pressure. For example, many physics experiments must take place in a vacuum chamber, a rigid chamber from which some of the air is pumped...

The shape of a small drop of liquid can be considered spherical, neglecting the effect of gravity. This drop can further be considered as two equal hemispherical drops put together due to surface tension. The forces acting on the spherical drop are due to the pressure of the liquid inside the drop, the pressure due to air outside the drop, and the force due to the surface tension acting on the two hemispherical drops.

The concept of static, stagnation, dynamic, and total pressure is fundamental in fluid dynamics, often explained using Bernoulli's equation: