Physics - Measurement
Mass
The quantity of matter contained in a body
Mass of a body is constant and does not change with time or place.
Mass is measured by a beam balance or physical balance.
The SI unit of mass is kilogram (kg).
Mass of a body can never be zero
Weight
The force with which a body is pulled towards the center of the Earth.
Weight of a body changes from place to place depending upon the gravity
Weight is measured by a spring balance.
The SI unit of weight is newton (N)
Weight of a body can be zero, as in space, where there is no gravity
Density
Mass per unit volume of a substance.
The SI unit of density is kg per cubic meter
Substances with more density are heavier than substance with low density
Density of a body decreases with increasing temperature and volume
Relative Density
The ratio of the density of a substance with that of water.
Relative density has no unit.
Relative density bottle compares the density of a liquid with that of water.
Area of irregular substance
The area of an irregular substance can be measured by placing it over a graph paper.
Lactometer
A hydrometer used to test the purity of milk.
Test Paper👇
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