Units, Unit system, SI unit and Fundamental & Basic Unit Conversions

There are many physical quantities in nature. And to understand each one we need different units because all the physical quantities cannot express or differentiated by single units.

Imagine saying, My weight is 50m and the temperature today is 30m and the distance I have to travel in order to reach my destination is 200m.

How does it sound?

The statement above sound senseless because weight, temperature, distance are three different physical quantities and they have been expressed by a single-unit, meter. As it is mentioned earlier different physical quantities cannot be understood by one single unit and so, there are different units for each of the physical quantities.

In order to measure any quantity, we need to fix a standard value of the unit so that we can measure a quantity and compare it with others.

Let’s take a simple example; we know that a bus is heavier than a car but exactly how many times? But, if we know that a bus is 80 times of standard unit of weight and car is 20 times the standard unit of weight then we can simply tell that a bus is 4 times heavier than the weight of a car.

Now, If I say, I have to study for 4 hours, then, anyone can understand that I have to study for 4 times the standard unit of time and hours denote the unit of time taken.

Unit system

There are three different system of the unit that is used to denote a certain unit of different physical quantity in that specific unit system:

1.     MKS System

2.     CGS System

3.     FPS System

In MKS System, the units of length, mass and time taken are meter, kilogram and second respectively and hence the name MKS.

Similarly, in CGS system, the units taken are centimeter, gram and second, and in FPS system, the units taken are foot, pound, and second.

In order to convert a unit of quantity from one system to another, you must know the conversion given below:

1 meter = 100 centimeter = 3.281 feet

1 kilogram = 1000 gram = 2.205 pound

SI System

In 1971, the authorized body named Conference Generale des Poids et Mesures or CGPM also known as General Conference on Weight and Measures held a meeting and decided a system of units which is known as the International System of Units. It is abbreviated as SI from the French name Le Systeme International d'Unites.  This system is widely used throughout the world.

As in the MKS system, the SI system also has the unit meter for length, kilogram for mass, and second for time.

Fundamental unit Conversion

Mass Conversions

1 Tonne = 10 Quintal = 1000 kilogram

1 Slug = 14.606 Kilogram

1 Kilogram = 2.205 Pound (lb)

1 Ounce = 28.3495 Gram

Length Conversions

1 Inch = 25.4 Millimeter = 2.54 Centimeter

1 Meter = 1.09 Yards = 3.281 Feet = 39.37 Inch

1 Foot = 12 Inches

1Yard = 3 Feet = 36 Inches

1 Mile = 1.609 Kilometer = 8 Furlong = 1760 Yard

Area Conversions

1 Acre = 4046.46 Square meter = 43560 Square feet = 0.04046 Hectare

Post a Comment

Your comment will be moderated.