Measurement

Introduction

  Physics is the branch of science which deals with the study of nature and natural phenomenon. According to the Einstein study of physics means a study of energy, mass, and their interaction. Mass and energy are interconvertible to each other. The mass is converted into energy and energy is converted into mass. These are not two distinct quantities.
  The physics is often called as 'science of measurement. It measures the physical quantities and established the relation between them.
  Measurement of physical quantity involves comparison of the physical quantity with its accepted standard unit. The result of a measurement of a physical quantity is expressed in terms of number or digit and the symbol of a unit. If a large number of physical quantities are measured. Most of the physical quantities are expressed in terms of the limited number of units.

Need Of Measurements
  In physics, we are to deal with a large number of physical quantities like length, mass, time, speed, acceleration, force, pressure etc. These quantities can give clear understanding if we can measure them. The need Afor measurement is clear from the following examples


1) Speed = Distance/Time
  We can find the speed if we can measure the distance traveled and the time taken to travel that distance.

ii) Acceleration = Force/Mass
  In order to find the acceleration produced in the body, we should know the magnitudes (i.e. measurement) of force acting on the body and mass of the body.

iii) Pressure = Force/Area
  Again we can find pressure if we measure the force acting and the area over which the force acts.

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