Unit Of Pressure In Cgs System

The Unit of Pressure in the CGS System: Unveiling the Barye

The CGS system, or Centimeter-Gram-Second system, is a variant of the metric system based on the centimeter as the unit of length, the gram as the unit of mass, and the second as the unit of time. While largely superseded by the SI (International System of Units), understanding the CGS system remains crucial for historical context and for interpreting older scientific literature. This article delves into the unit of pressure within the CGS system: the barye.

What is Pressure and How is it Measured?

Pressure is defined as the force applied perpendicularly to a surface per unit area. Understanding this definition is crucial for grasping the units used to measure it. A larger force applied over a smaller area results in higher pressure, while the same force spread over a larger area results in lower pressure. This concept is fundamental in various scientific fields, including physics, chemistry, and engineering. Think of the pressure in your car tires—a larger force (more air) in a smaller volume (tire) creates higher pressure.

Introducing the Barye: The CGS Unit of Pressure

In the CGS system, pressure is measured in baryes (Ba). One barye is defined as one dyne per square centimeter (dyn/cm²). Let's break this down:

• Dyne: The unit of force in the CGS system. One dyne is the force required to accelerate a mass of one gram at a rate of one centimeter per second squared (1 g·cm/s²).
• Square Centimeter (cm²): The unit of area in the CGS system.

Therefore, 1 Ba = 1 dyn/cm² = 1 g·cm⁻¹·s⁻². This signifies that one barye is the pressure exerted by a force of one dyne acting on an area of one square centimeter.

Barye vs. Pascal: The SI Equivalent

The SI unit of pressure is the pascal (Pa), defined as one newton per square meter (N/m²). To convert between baryes and pascals, we need to consider the conversion factors between the CGS and SI units:

• 1 N = 10⁵ dyn
• 1 m = 10² cm

Therefore, 1 Pa = 1 N/m² = (10⁵ dyn)/(10⁴ cm²) = 10 dyn/cm² = 10 Ba. This means that 1 pascal is equal to 10 baryes.

Applications and Context of the Barye

While the barye is less commonly used today compared to the pascal, understanding it provides valuable insight into the history of pressure measurement and the development of the metric system. You might encounter the barye in older scientific texts or specialized applications within specific fields that still utilize the CGS system. It’s a crucial unit for understanding the foundational concepts of pressure and its measurement.

In Summary:

The barye (Ba), the CGS unit of pressure, offers a historical perspective on pressure measurement. While the pascal (Pa) is the preferred SI unit, understanding the barye and its relationship to the pascal is essential for interpreting older scientific literature and appreciating the evolution of measurement units in physics. Remember, 1 Pa = 10 Ba. This knowledge enhances your understanding of the fundamental concepts of pressure and its measurement across different systems.