< Physics, Technology and Society
< SI units
< Fundamental and Derived Units
< Least Count
< Accuracy and Precision of Measuring Instruments
< Errors in Measurement
< Significant Figures
< Dimensions of Physical Quantities
< Dimensional Analysis and its Applications
●Physics , Technology and Society
1.1 Physics, Technology and Society
Science is a systematic attempt to understand natural phenomena in as much detail and depth as possible and use the knowledge, so gained to predict, modify and control phenomena. Science is exploring, experimenting and predicting from
what we see around us.
In physics, we attempt to explain diverse physical phenomena in terms of a few concepts and laws. The effort is to see the physical world as manifestation of some universal laws in different domains and conditions. The connection between physics, technology and society can be seen in many examples. The discipline of
thermodynamics arose from the need to understand and improve the working of
heat engines. Also wireless communication technology followed from the
discovery of the basic laws of electricity and magnetism. Let another important
example of physics giving rise to technology is the silicon chip that triggered the
computer revolution in the last three decades of the twentiath century. Hence, we
observe that how much strong influence physics is having on technology
1.2 SI Units
The quantities by means of which we describe the laws of physics are called physical quantities. To measure a physical quantity, some standard unit of that quantity is required, e g. . , if length of some metal rod is measured to be 20 m, then
m is the unit of length and 20 is the numerical value. So,
Physical quantity = Numerical value × Unit
Important points 👉🏻
👉🏻● If the numerical value of any physical quantity in d ifferent units u1 and u2 are n1 and n2Note
● If the numerical value of any physical quantity in different units u1
and u2
are n1
and n2
respectively, then n1u1=n2u2.
👉🏻● As the unit will change, numerical value will also change, e g. . , acceleration due to gravity,
g = 32 fts–2 = 9.8 ms–2
.
respectively, then n1u1=n2u2.
👉🏻● As the unit will change, numerical value will also change, e g. . , acceleration due to gravity,
g = 32 fts–2 = 9.8 ms–2
.
