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Newton's Laws Of Motion
Newton's laws of motion are three physical laws that describe the relationship between the motion of an object and the forces acting on it. These laws, which provide the basis for Newtonian mechanics, can be paraphrased as follows: # A body remains at rest, or in motion at a constant speed in a straight line, unless it is acted upon by a force. # At any instant of time, the net force on a body is equal to the body's acceleration multiplied by its mass or, equivalently, the rate at which the body's momentum is changing with time. # If two bodies exert forces on each other, these forces have the same magnitude but opposite directions. The three laws of motion were first stated by Isaac Newton in his ''Philosophiæ Naturalis Principia Mathematica'' (''Mathematical Principles of Natural Philosophy''), originally published in 1687. Newton used them to investigate and explain the motion of many physical objects and systems. In the time since Newton, new insights, especially around t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physical Laws
Scientific laws or laws of science are statements, based on reproducibility, repeated experiments or observations, that describe or prediction, predict a range of natural phenomena. The term ''law'' has diverse usage in many cases (approximate, accurate, broad, or narrow) across all fields of natural science (physics, chemistry, astronomy, geoscience, biology). Laws are developed from data and can be further developed through mathematics; in all cases they are directly or indirectly based on empirical evidence. It is generally understood that they implicitly reflect, though they do not explicitly assert, causal relationships fundamental to reality, and are discovered rather than invented. Scientific laws summarize the results of experiments or observations, usually within a certain range of application. In general, the accuracy of a law does not change when a new theory of the relevant phenomenon is worked out, but rather the scope of the law's application, since the mathematics o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Limit (mathematics)
In mathematics, a limit is the value that a function (or sequence) approaches as the argument (or index) approaches some value. Limits of functions are essential to calculus and mathematical analysis, and are used to define continuity, derivatives, and integrals. The concept of a limit of a sequence is further generalized to the concept of a limit of a topological net, and is closely related to limit and direct limit in category theory. The limit inferior and limit superior provide generalizations of the concept of a limit which are particularly relevant when the limit at a point may not exist. Notation In formulas, a limit of a function is usually written as : \lim_ f(x) = L, and is read as "the limit of of as approaches equals ". This means that the value of the function can be made arbitrarily close to , by choosing sufficiently close to . Alternatively, the fact that a function approaches the limit as approaches is sometimes denoted by a right arrow (→ or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Celestial Mechanics And Dynamical Astronomy
''Celestial Mechanics and Dynamical Astronomy'' is a scientific journal covering the fields of astronomy and astrophysics. It was established as ''Celestial Mechanics'' in June 1969. The journal is published by Springer Science+Business Media and the editor-in-chief is Alessandra Celletti ( University of Rome Tor Vergata), while Sylvio Ferraz-Mello (University of São Paulo) is honorary editor. Abstracting and indexing The journal is abstracted and indexed in: According to the ''Journal Citation Reports'', the journal has a 2020 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a type of journal ranking. Journals with higher impact factor values are considered more prestigious or important within their field. The Impact Factor of a journa ... of 1.664. References External links * Astronomy journals Academic journals established in 1969 Springer Science+Business Media academic journals Monthly journals English-langua ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Variable Mass System
In mechanics, a variable-mass system is a collection of matter whose mass varies with time. It can be confusing to try to apply Newton's second law of motion directly to such a system. Instead, the time dependence of the mass ''m'' can be calculated by rearranging Newton's second law and adding a term to account for the momentum carried by mass entering or leaving the system. The general equation of variable-mass motion is written as :\mathbf_ + \mathbf_\frac = m where Fext is the net external force on the body, vrel is the relative velocity of the escaping or incoming mass with respect to the center of mass of the body, and v is the velocity of the body. In astrodynamics, which deals with the mechanics of rockets, the term ''v''rel is often called the effective exhaust velocity and denoted ''v''''e''. Derivation There are different derivations for the variable-mass system motion equation, depending on whether the mass is entering or leaving a body (in other words, whethe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Studies In History And Philosophy Of Modern Physics
''Studies in History and Philosophy of Science'' is a series of three peer-reviewed academic journals published by Elsevier. It was established in 1970 as a single journal, and was split into two sections–''Studies in History and Philosophy of Science Part A'' and ''Studies in History and Philosophy of Science Part B: Studies in History and Philosophy of Modern Physics''–in 1995. In 1998, a third section, ''Studies in History and Philosophy of Science Part C: Studies in History and Philosophy of Biological and Biomedical Sciences'', was created. In January 2021, all three sections were merged back into Part A, ''Studies in History and Philosophy of Science''. Part A ''Studies in History and Philosophy of Science Part A'' was established in 1970 and is published 7 times per year. It covers the philosophy and history of science. The editor-in-chief is Darrell P. Rowbottom (Lingnan University). According to the ''Journal Citation Reports'', the journal has a 2017 impact factor of 0 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Absolute Space And Time
Absolute space and time is a concept in physics and philosophy about the properties of the universe. In physics, absolute space and time may be a preferred frame. Early concept A version of the concept of absolute space (in the sense of a preferred frame) can be seen in Aristotelian physics. Robert S. Westman writes that a "whiff" of absolute space can be observed in Copernicus's '' De revolutionibus orbium coelestium'', where Copernicus uses the concept of an immobile sphere of stars. Newton Originally introduced by Sir Isaac Newton in '' Philosophiæ Naturalis Principia Mathematica'', the concepts of absolute time and space provided a theoretical foundation that facilitated Newtonian mechanics. According to Newton, absolute time and space respectively are independent aspects of objective reality: Absolute, true and mathematical time, of itself, and from its own nature flows equably without regard to anything external, and by another name is called duration: relative, appar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inertial Observer
In classical physics and special relativity, an inertial frame of reference (also called an inertial space or a Galilean reference frame) is a frame of reference in which objects exhibit inertia: they remain at rest or in uniform motion relative to the frame until acted upon by external forces. In such a frame, the laws of nature can be observed without the need to correct for acceleration. All frames of reference with zero acceleration are in a state of constant rectilinear motion (straight-line motion) with respect to one another. In such a frame, an object with zero net force acting on it, is perceived to move with a constant velocity, or, equivalently, Newton's first law of motion holds. Such frames are known as inertial. Some physicists, like Isaac Newton, originally thought that one of these frames was absolute — the one approximated by the fixed stars. However, this is not required for the definition, and it is now known that those stars are in fact moving, relative t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inertia
Inertia is the natural tendency of objects in motion to stay in motion and objects at rest to stay at rest, unless a force causes the velocity to change. It is one of the fundamental principles in classical physics, and described by Isaac Newton in his Newton%27s_laws_of_motion#First, first law of motion (also known as The Principle of Inertia). It is one of the primary manifestations of mass, one of the core quantitative properties of physical systems. Newton writes: In his 1687 work ''Philosophiæ Naturalis Principia Mathematica'', Newton defined inertia as a property: History and development Early understanding of inertial motion Joseph NeedhamProfessor John H. Lienhard points out the Mozi (book), Mozi – based on a Chinese text from the Warring States period (475–221 BCE) – as having given the first description of inertia. Before the European Renaissance, the prevailing theory of motion in western philosophy was that of Aristotle (384–322 BCE). On the surface ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skylab And Earth Limb - GPN-2000-001055
Skylab was the United States' first space station, launched by NASA, occupied for about 24 weeks between May 1973 and February 1974. It was operated by three trios of astronaut crews: Skylab 2, Skylab 3, and Skylab 4. Skylab was constructed from a repurposed Saturn V third stage (the S-IVB), and took the place of the stage during launch. Operations included an orbital workshop, a solar observatory, Earth observation and hundreds of experiments. Skylab's orbit eventually decayed and it disintegrated in the atmosphere on July 11, 1979, scattering debris across the Indian Ocean and Western Australia. Overview Skylab was the only space station operated exclusively by the United States. A Space Station Freedom, permanent station was planned starting in 1988, but its funding was canceled and U.S. participation shifted to the International Space Station in 1993. Skylab had a mass of with a Apollo command and service module (CSM) attached and included a workshop, a solar observa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
OpenStax
OpenStax (formerly OpenStax College) is a nonprofit educational technology initiative based at Rice University. Since 2012, OpenStax has created peer-reviewed, openly licensed textbooks, which are available in free digital formats and for a low cost in print. Most books are also available in Kindle versions on Amazon.com and in the iBooks Store. OpenStax's first textbook was ''College Physics'', which was published online, in print, and in iBooks in 2012. OpenStax launched OpenStax Tutor Beta in June 2017, adaptive courseware based on cognitive science principles, machine learning, and OpenStax content. However, it was announced in October 2022 that Tutor was being discontinued. Aiming to compete with major publishers' offerings, the project was initially funded by the Bill and Melinda Gates Foundation, the William and Flora Hewlett Foundation, the Michelson 20 Million Minds Foundation, and the Maxfield Foundation. All textbook content is licensed under Creative Commons At ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physical Review Special Topics - Physics Education Research
''Physical Review'' is a peer-reviewed scientific journal. The journal was established in 1893 by Edward Nichols. It publishes original research as well as scientific and literature reviews on all aspects of physics. It is published by the American Physical Society (APS). The journal is in its third series, and is split in several sub-journals each covering a particular field of physics. It has a sister journal, ''Physical Review Letters'', which publishes shorter articles of broader interest. History ''Physical Review'' commenced publication in July 1893, organized by Cornell University professor Edward Nichols and helped by the new president of Cornell, J. Gould Schurman. The journal was managed and edited at Cornell in upstate New York from 1893 to 1913 by Nichols, Ernest Merritt, and Frederick Bedell. The 33 volumes published during this time constitute ''Physical Review Series I''. The American Physical Society (APS), founded in 1899, took over its publication in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physics Education
Physics education or physics teaching refers to the education methods currently used to teach physics. The occupation is called physics educator or physics teacher. Physics education research refers to an area of pedagogical research that seeks to improve those methods. Historically, physics has been taught at the high school and college level primarily by the lecture method together with laboratory exercises aimed at verifying concepts taught in the lectures. These concepts are better understood when lectures are accompanied with demonstration, hand-on experiments, and questions that require students to ponder what will happen in an experiment and why. Students who participate in active learning for example with hands-on experiments learn through self-discovery. By trial and error they learn to change their preconceptions about phenomena in physics and discover the underlying concepts. Physics education is part of the broader area of science education. History In Ancient Greec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
