PHYSICAL QUANTITY

SCIENCE

Generally we know various subject which are related to Science, but the main part of Science are,

1. Physical Science

2. Life Science

also Physical Science is divided in two parts

1.Physics

2 Chemistry

 Today we will describe about System of Measurements and Measuring Devices

System of Measurements and Measuring Devices

First we have to learn the difference between 

• which think we can measure
• and what we measure

Actually we dont measure the think, we just measure their mass, volume, density, weight etc.

Physical Quantity:Whichever we can measure they are called Physical Quantity.

Ex.-Length, Width, Height, Time, Mass, Temperature etc.

 not Wood, Stone, Aggregate, Water, they are the Particle and we Measure their Physical Quantity

Physical Quantity is divided in Two parts

1.Scalar Quantity

2. Vector Quantity

generally in our life we will see that few quantity never depends on direction,just like mass off a Particle. From any direction if you keep a 5 kg mango with another 5 kg mango then it will be 10 kg, that we can easily add or sub-struct the Quantity,

 If you puss a table and your friend from opposite direction.then it will not move but if both of you are puss it from same direction then it will move. that is why here you can see that the applying force is depending on the direction.   

here the mass is Scalar Quantity and Force is Vector Quantity.

1.Scalar Quantity: The Physical Quantity which depends on its magnitude only, not on its direction.those are called Scalar Quantity.

Ex.- Mass.Length, Area, Volume, Temperature, Time etc.

2. Vector Quantity: The Physical Quantity which depends on both Magnitude and Direction, they are called Vector Quantity.

Ex.-Weight, Acceleration, Force, Velocity, Displacement

Generally we apply simple addition and simple Substitution for Scalar Quantity

but we can  not apply simple addition and substitution for vector quantity, we must have to apply Vector Addition and Vector Substitution theory for their calculation.