Matter : Anything which occupy some space , can be divide, and it can be perceived
By our sense organs (eye, nose, ear, tongue, and skin ) is called a matter.
Mass : Mass of a body is the total quantity of matter contained in the body.
Description : Each and every substance in the world , whether living or non-living is a matter. Mass is a constant quantity of a matter .
Mass of a body is measured with the help of a common balance .
Mass is a scalar quantity i.e it has only magnitude but no direction .
The C.G. S unit of mass is gm and S.I unit is Kg.
The fundamental properties of matter
The fundamental properties of a matter is given below;
· Volume : Every matter living or non- living have a definite volume
· Porosity : Every matter posses very minute porus , this property is called porosity.
· Gravitation : Any two matter attract each other .
· Divisibility : All matter can be divided into very small parts .
· Inertia : An inainimate matter cannot , by itself , change its state of rest or Motoion.
· Cohesion : Different molecule of the same substance attract each other.
· Density : The mass of unit substance is called its density.
Weight of a body , how it is measured ,and its unit
Weight : The force with which the earth attracts the body towards its own centre is called the weight of the body.
The weight of a body is measured by a spring balance .
Weight of a body, being a force is a vector quantity. We know from
In this case, the acceleration of the body is the acceleration due to gravity.Hence , if W be the weight of the body, then from the above definition W = mg , where ‘g’ is the acceleration due to gravity.
If g = 1, then m =W. Thus mass of a body is numerically equal to the weight of a body at a place of unit acceleration . At the centre of the earth g = 0 hence weight of a body is zero at the centre of the earth.
Units : Weight being a force, its S.I unit is
They are related as
1Kgf =1000 gf = 9.8 N
1gf =980 dynes , and
1 N = 105 dynes where g =9.8 m/s2
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