STATE THE CGS UNIT OF PRESSURE . STATE THE RELATION BETWEEN THE SI AND CGS UNIT OF PRESSURE . DON'T WANT GOOGLE ANSWERS
Answers
Answer:
The cgs base pressure unit is barye (Ba).The SI unit for pressure is Pascal, or Pa. 1 Pa = 1 N/m2
. The Earths atmosphere at sea level has a pressure
of 1.013 × 105
Pa.
The cgs unit for pressure does not have a special name. It is dyne/cm2
. The Earths atmosphere at sea level
has a pressure of 1.013 × 106
dyn/cm2
.
1 dyne/cm2
represents 10 times less pressure than a Pascal. 10 dyn/cm2
= 1 Pa.
[Other common units for pressure are: 1 torr = 133.3 Pa, 1 bar = 105
Pa, and 1 atm = 1.013 × 105
Pa.]
Answer:
Explanation:
THE CGS UNIT OF PRESSURE is barye
Pressure (symbol: p or P) is the force applied perpendicular to the surface of an object per unit area over which that force is distributed.:445[1] Gauge pressure (also spelled gage pressure)[a] is the pressure relative to the ambient pressure.
Various units are used to express pressure. Some of these derive from a unit of force divided by a unit of area; the SI unit of pressure, the pascal (Pa), for example, is one newton per square metre (N/m2); similarly, the pound-force per square inch (psi) is the traditional unit of pressure in the imperial and U.S. customary systems. Pressure may also be expressed in terms of standard atmospheric pressure; the atmosphere (atm) is equal to this pressure, and the torr is defined as 1⁄760 of this. Manometric units such as the centimetre of water, millimetre of mercury, and inch of mercury are used to express pressures in terms of the height of column of a particular fluid in a manometer.
Pressure is the amount of force applied at right angles to the surface of an object per unit area. The symbol for it is p or P.[2] The IUPAC recommendation for pressure is a lower-case p.[3] However, upper-case P is widely used. The usage of P vs p depends upon the field in which one is working, on the nearby presence of other symbols for quantities such as power and momentum, and on writing style.
Formula
Conjugate variables
of thermodynamics
Pressure Volume
(Stress) (Strain)
Temperature Entropy
Chemical potential Particle number
Pressure force area.svg
Mathematically:
{\displaystyle p={\frac {F}{A}},}{\displaystyle p={\frac {F}{A}},}[4]
where:
{\displaystyle p}p is the pressure,
{\displaystyle F}F is the magnitude of the normal force,
{\displaystyle A}A is the area of the surface on contact.
Pressure is a scalar quantity. It relates the vector area element (a vector normal to the surface) with the normal force acting on it. The pressure is the scalar proportionality constant that relates the two normal vectors:
{\displaystyle d\mathbf {F} _{n}=-p\,d\mathbf {A} =-p\,\mathbf {n} \,dA.}{\displaystyle d\mathbf {F} _{n}=-p\,d\mathbf {A} =-p\,\mathbf {n} \,dA.}
The minus sign comes from the fact that the force is considered towards the surface element, while the normal vector points outward. The equation has meaning in that, for any surface S in contact with the fluid, the total force exerted by the fluid on that surface is the surface integral over S of the right-hand side of the above equation.
It is incorrect (although rather usual) to say "the pressure is directed in such or such direction". The pressure, as a scalar, has no direction. The force given by the previous relationship to the quantity has a direction, but the pressure does not. If we change the orientation of the surface element, the direction of the normal force changes accordingly, but the pressure remains the same.
Pressure is distributed to solid boundaries or across arbitrary sections of fluid normal to these boundaries or sections at every point. It is a fundamental parameter in thermodynamics, and it is conjugate to volume.