Difference between revisions of "Physics"

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The study of energy is known as Physics. That is the most general definition of Physics you can think of, which gives one some idea of the vastness of topics coming under Physics. ''Everything'' concerning energy in some form or the other is covered by Physics.
 
The study of energy is known as Physics. That is the most general definition of Physics you can think of, which gives one some idea of the vastness of topics coming under Physics. ''Everything'' concerning energy in some form or the other is covered by Physics.
--[[User:Bubka|Bubka]] 04:32, 4 November 2006 (EST)
 
 
 
== Branches of Classical Physics ==
 
== Branches of Classical Physics ==
  
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* Electromagnetism
 
* Electromagnetism
 
We shall now look into them one by one.
 
We shall now look into them one by one.
--[[User:Bubka|Bubka]] 04:39, 4 November 2006 (EST)
 
  
 
== Mechanics ==
 
== Mechanics ==
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Among the various properties of matter are elasticity, surface tension, viscosity etc. But the most important one is gravity. Gravity is indeed considered one of the most mysterious things not only in physics but in science as a whole. I'll tell you more about gravity when we come to modern physics.
 
Among the various properties of matter are elasticity, surface tension, viscosity etc. But the most important one is gravity. Gravity is indeed considered one of the most mysterious things not only in physics but in science as a whole. I'll tell you more about gravity when we come to modern physics.
  
 
--[[User:Bubka|Bubka]] 05:31, 4 November 2006 (EST)
 
  
 
== See also ==
 
== See also ==

Revision as of 07:13, 4 November 2006

Template:Wikify The study of energy is known as Physics. That is the most general definition of Physics you can think of, which gives one some idea of the vastness of topics coming under Physics. Everything concerning energy in some form or the other is covered by Physics.

Branches of Classical Physics

Physics as we knew it till the end of the nineteenth century is known now as Classical physics. It is broadly classified into the following branches:

  • Mechanics
  • Accoustics
  • Optics
  • Thermodynamics
  • Electromagnetism

We shall now look into them one by one.

Mechanics

Etymologically, the study of machines is called Mechanics. It broadly covers kinematics, mechanical forces, work, power, and energy, and various properties of matter.

Kinematics is the study of (relative) motion - displacement, velocity, acceleration etc. The two relations at the heart of kinematics are: $v=\frac{dx}{dt}$, and $a=\frac{d^2x}{dt^2}$ where $x$ is displacement, $v$ is velocity, $a$ is acceleration, and $t$ is time. The simplest topic under kinematics is uniform rectilinear motion. Other simple topics are projectile motion, uniform circular motion, simple harmonic motion etc.

Then we move on to the study of forces, which is almost fully summarized by the three famous laws of motion due to Newton:

  • A body continues to be in its state of uniform rectilinear motion until it is disturbed by an external force. This property is known as inertia.
  • The rate of change of momentum of a body with respect to time is directly proportional to the force acting on it.
  • Every action as an equal and opposite reaction.

Here we come across two completely new quantities: mass and force. Mass is the one of the two most basic intrinsic properties of a body. It is a measure of its inertia. Momentum is defined as the product of the mass and velocity of a body. Force is something that changes or tends to change the momentum of a body.

Mechanical work is defined by the relation $W = \displaystyle\int^{x_f}_{x_i} F\,dx$ where $W$ is work done, $F$ is force, $x$ is displacement, and subscripts $i$ and $f$ denote the initial and final states respectively. Similarly, mechanical power is defined as $P = \displaystyle\int^{v_f}_{v_i} F\,dv$ where $P$ is power delivered and $v$ is velocity. Energy is the other basic intrinsic property of a body. Mechanical energy is simply the capacity of a body to do mechanical work.

Among the various properties of matter are elasticity, surface tension, viscosity etc. But the most important one is gravity. Gravity is indeed considered one of the most mysterious things not only in physics but in science as a whole. I'll tell you more about gravity when we come to modern physics.


See also

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