Ingles

Colegio cafan”bellavista”ced
Learn to learn: recognize the characteristics of units of measure or of time and time and how it affects our life.
Learn to do: resolve situation problem with base to the measure and time
* Lear to be : value and appropriating of the knowledge and share them in class
Cognitive activator: solve the cryptogram next
The Physics always strives to present a clearpicture of Xch fclgepg zayzlg gxiewbg xm fibgbcx z pabzi fepxoib mvthe world that surrounds usxch ymias xczx goiimocsg og |
* Information
Like all other sciences, physics is based on experimental observations and quantitative
measurements. The main objectives of physics are to identify a limited number
of fundamental laws that govern natural phenomena and use them to develop
theoriesthat can predict the results of future experiments. The fundamental laws
used in developing theories are expressed in the language of mathematics, the
tool that provides a bridge between theory and experiment.
When there is a discrepancy between the prediction of a theory and experimental
results, new or modified theories must be formulated to remove the discrepancy.
Many times a theory issatisfactory only under limited conditions; a more
general theory might be satisfactory without such limitations. For example, the
laws of motion discovered by Isaac Newton (1642–1727) accurately describe the
motion of objects moving at normal speeds but do not apply to objects moving at
speeds comparable with the speed of light. In contrast, the special theory of relativity
developed later byAlbert Einstein (1879–1955) gives the same results as Newton’s
laws at low speeds but also correctly describes the motion of objects at speeds
approaching the speed of light. Hence, Einstein’s special theory of relativity is a
more general theory of motion than that formed from Newton’s laws.
Classical physics includes the principles of classical mechanics, thermodynamics,
optics, andelectromagnetism developed before 1900. Important contributions to
classical physics were provided by Newton, who was also one of the originators of calculus as a mathematical tool. Major developments in mechanics continued in
the 18th century, but the fields of thermodynamics and electromagnetism were
not developed until the latter part of the 19th century, principally because before
that time theapparatus for controlled experiments in these disciplines was either
too crude or unavailable.
Standards of length, mass , and time
To describe natural phenomena, we must make measurements of various aspects
of nature. Each measurement is associated with a physical quantity, such as the
length of an object.
If we are to report the results of a measurement to someone who wishes to
reproducethis measurement, a standard must be defined. It would be meaningless
if a visitor from another planet were to talk to us about a length of 8 “glitches” if
we do not know the meaning of the unit glitch. On the other hand, if someone
familiar with our system of measurement reports that a wall is 2 meters high and
our unit of length is defined to be 1 meter, we know that the height of the wall istwice our basic length unit. Whatever is chosen as a standard must be readily
accessible and must possess some property that can be measured reliably. Measurement
standards used by different people in different places—throughout the Universe—
must yield the same result. In addition, standards used for measurements
must not change with time.
In 1960, an international committee established aset of standards for the fundamental
quantities of science. It is called the SI (Système International), and its
fundamental units of length, mass, and time are the meter, kilogram, and second,
respectively. Other standards for SI fundamental units established by the committee
are those for temperature (the kelvin), electric current (the ampere), luminous
intensity (the candela), and the...