What exactly is physics?

Question

I'm going to be in a physics class next year and I kind of know what it is but not completely. What's it used for?
Thanks.

Answer 1

Physics (Greek: φύσις (phúsis), "nature" and φυσικῆ (phusiké), "knowledge of nature") is the branch of science concerned with the discovery and characterization of universal laws which govern matter, energy, space, and time. The role of physics, then, is to provide a logically ordered picture of nature in agreement with experience.

Although physicists study a wide variety of phenomena, there are certain theories that are used by all physicists. Each of these theories has been tested in numerous experiments and proven to be a correct approximation of nature within its domain of validity. For example, the theory of classical mechanics accurately describes the motion of objects, provided that they are much larger than atoms and move much slower than the speed of light. While these theories have long been well-understood, they continue to be areas of active research—for example, a remarkable aspect of classical mechanics known as chaos was discovered in the 20th century, three centuries after its original formulation by Isaac Newton (1642–1727). The "central theories" are important tools for research into more specialized topics, and all physicists are expected to be literate in them.

Typical thermodynamic system - heat moves from hot (boiler) to cold (condenser) and work is extracted Classical mechanics is a model of the physics of forces acting upon bodies. It is often referred to as "Newtonian mechanics" after Newton and his laws of motion.

Classical mechanics is subdivided into statics, which models objects at rest, kinematics, which models objects in motion, and dynamics, which models objects subjected to forces. It is superseded by relativistic mechanics for systems moving at large velocities near the speed of light, quantum mechanics for systems at small distance scales, and relativistic quantum field theory for systems with both properties. Nevertheless, classical mechanics is still very useful, because it is much simpler and easier to apply than these other theories, and it has a very large range of approximate validity.

Classical mechanics can be used to describe the motion of human-sized objects (such as tops and baseballs), many astronomical objects (such as planets and galaxies), and certain microscopic objects (such as organic molecules.)

Electromagnetism -- called also Electromagnetics -- is the physics of the electromagnetic field, a field that results from the presence and motion of charged particles and exerts forces on them. The sub-discipline of electrodynamics describes the behavior of moving charged particles interacting with electromagnetic fields. Electromagnetism encompasses various real-world electromagnetic phenomena. In fact, light is an oscillating electromagnetic field that is radiated from accelerating charged particles.
Aside from gravity, most of the forces in everyday experience are ultimately a result of electromagnetism.

Thermodynamics is the branch of physics that deals with the action of heat and the conversions from one to another of various forms of energy. Thermodynamics is particularly concerned with how these affect temperature, pressure, volume, mechanical action, entropy, and work. Statistical mechanics, a related theory, is the branch of physics that analyzes macroscopic systems by applying statistical principles to their microscopic constituents. It can be applied to calculate the thermodynamic properties of bulk materials from the properties of individual molecules, which is the basis of statistical thermodynamics.

The theory of relativity is:
a physical theory which is based on the two postulates: (1) that the speed of light in a vacuum is constant and independent of the source or observer and (2) that the mathematical forms of the laws of physics are invariant in all inertial systems-- called also special relativity, special theory of relativity. It leads to the assertion of the equivalence of mass and energy and of change in mass,dimension, and time with increased velocity. an extension of special relativity to include transformations between non-inertial frames-- also called general relativity or the general theory of relativity. It is formulated using differential geometry and interprets gravity as a distortion of spacetime caused by the presence of mass or energy.

Quantum mechanics is the branch of mathematical physics treating atomic and subatomic systems and their interaction with radiation in terms of observable quantities. It is based on the observation that all forms of energy are released in discrete units or bundles called quanta. Quantum mechanics provides a physical theory of matter that is based on the concept of the possession of wave properties by elementary particles, affords a mathematical interpretation of the structure and interactions of matter on the basis of these properties, and incorporates within it quantum theory and the uncertainty principle -- called also wave mechanics. Remarkably, quantum theory typically permits only probable or statistical calculation of the observed features of subatomic particles, understood in terms of wavefunctions. The discovery of quantum mechanics in the early 20th century revolutionized physics, and quantum mechanics is fundamental to most areas of current research.

To view a really cool table on all the theories and concepts go to: http://en.wikipedia.org/wiki/Physics

Happy Studying

Kind regards, Wendy

Answer 2

Physics is the most basic science, from a reductionist point of view. It attempts to reduce physical processes to a basic mathematical description of quantifiable properties and forces. In practice, this means that very complex things such as biology, economics, and stamp collecting are beyond its reach, and a more phenomenological approach is needed to make headway in such cases. A good (tongue in cheek) rule of thumb is that if it's bigger than a molecule but smaller than a planet, physicists aren't interested.

What's it used for? Technology! As technology advances, the fundamental limits of what is achievable using a given general technique are approached. Physics helps us understand those limits, and how best to approach them. A biproduct often is that entirely new ways of doing things are conceived.

Answer 3

Physics includes many topics such as gravity, light, and generally how the world works.
You will probably be studying kinematics and newton's laws. Kinematics are how things move such as figuring out how far a cannonball will go if you know how fast you shot it at. Newton's laws compare forces and acceleration. (Acceleration is how your speed changes over time).
Newton's laws:
1. An object in motion stays in motion unless acted upon by another force.
2. The acceleration of an object is Force divided by it's mass.
3. For every force, there is an equal and opposite force.

Answer 4

Physics is the learn of the family (that are interactions in theory) between debris, structures or actual measurements. to illustrate, the main severe purpose of classical mechanics is to make certain the trajectories of debris or gadgets understanding the forces (interactions) that act on them. Thermodynamics supplies us family between warmth, temperature, thermal potential and different values. different matters could be extra mathematically orientated, however the main considerable purpose is to make certain family or actual rules in a manner this is consistent with experimental observations.

Answer 5

It is the study of the laws of nature and it is used in all forms of engineering. Without physics we would no TV, Radio,Space Ships, Ocean Liners, etc, etc.

Answer 6

physics is basically the observation of matter and energy, how the two interact and what effect they have on eachother and the world. when i took physics, it was pretty much just memorizing a bunch of formulas and applying them to problems. almost like algebra.

Answer 7

i guess it tells you why things are the way they are.
you'll learn about gravity, inertia, energy, ect., why things happen, the laws of physics, and theories of physics.
thats the only way i can really explain it.

Answer 8

its is the study of light, forces, and i think that covers it lol