Supplementary quantities are geometrical quantities of circle and sphere . Supplementary physical quantity is used for calculation on secondary level .
The two supplementary physical quantities are
( i ) Plane angle
( ii ) Solid angle
The quantities which do not depend upon other quantities for their complete definition are known as fundamental quantities.
There are 7 fundamental quantities .
eg- length , mass , current etc .
and Derived quantities are those quantities that can be expressed in terms of fundamental quantities .
eg- density , velocity , momentum , energy etc .
Physical quantities can be measured in a proper unit and it has a numerical value . Physical quantities are verified scientifically and help us to define laws of physics .
eg. mass, amount of substance, length, time, temperature, electric current, light intensity, force, velocity, density, momentum , energy .
And Non- Physical quantities are those quantities that can not be measured by any device , does not have unit or magnitude themselves . Sometimes these quantities can be compared to each other .
eg. Rudeness, Love , Happiness, Sadness , Proudness, Respect, Pride, Hate, Angry, Loyalty and Stupidity .
The continuity equation is a mathematical expression of the law of conservative of mass in fluid dynamics .
This equation defines the steady flow of a fluid in a tube. It states that if flow of a fluid is steady then the mass of the fluid entering per second at one end is equal to the mass of fluid leaving per second at the other end .
Barometer is a device used to measure atmospheric pressure . In principle , any liquid can be used to fill the Barometer, but mercury is the substance of choice because its high density makes possible an instrument of reasonable size . It uses liquid mercury to predict the weather by tracking atmospheric pressure changes resulting from the movement of warm and cold weather systems .
We know that in an statics fluid pressure in horizontal direction will be constant because of equi-pressure surface but in case of vertical Variation it’s Vary .If the weight of the fluid can be neglected, the pressure in a fluid is the same throughout its volume. But often the fluid’s weight is not negligible and under such condition pressure increases with increasing depth below the surface .
dp/dy = ρg . ( This is the general expression of variation of pressure with depth ) .