Difference between revisions of "Physics"
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where <math>x</math> is displacement, <math>v</math> is velocity, <math>a</math> is acceleration, and <math>t</math> is time. | where <math>x</math> is displacement, <math>v</math> is velocity, <math>a</math> is acceleration, and <math>t</math> is time. | ||
The simplest topic under kinematics is uniform rectilinear motion. Other simple topics are projectile motion, uniform circular motion, simple harmonic motion etc. | The simplest topic under kinematics is uniform rectilinear motion. Other simple topics are projectile motion, uniform circular motion, simple harmonic motion etc. | ||
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| + | 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 <math>W = \displaystyle\int^{x_f}_{x_i} F\,dx</math> where <math>W</math> is work done, <math>F</math> is force, <math>x</math> is displacement, and subscripts <math>i</math> and <math>f</math> denote the initial and final states respectively. Similarly, mechanical power is defined as <math>P = \displaystyle\int^{v_f}_{v_i} F\,dv</math> where <math>P</math> is power delivered and <math>v</math> 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. | ||
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== See also == | == See also == | ||
* [[Physics books]] | * [[Physics books]] | ||
Revision as of 06:26, 4 November 2006
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. --Bubka 04:32, 4 November 2006 (EST)
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. --Bubka 04:39, 4 November 2006 (EST)
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:
, and
where 
is displacement, 
is velocity, 
is acceleration, and 
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 
where 
is work done, 
is force, is displacement, and subscripts 
and 
denote the initial and final states respectively. Similarly, mechanical power is defined as 
where 
is power delivered and 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.
See also
This article is a stub. Help us out by expanding it.
