Euler's laws of motionIn classical mechanics, Euler's laws of motion are equations of motion which extend Newton's laws of motion for point particle to rigid body motion. They were formulated by Leonhard Euler about 50 years after Isaac Newton formulated his laws. Euler's first law states that the rate of change of linear momentum p of a rigid body is equal to the resultant of all the external forces Fext acting on the body: Internal forces between the particles that make up a body do not contribute to changing the momentum of the body as there is an equal and opposite force resulting in no net effect.
Four-accelerationIn the theory of relativity, four-acceleration is a four-vector (vector in four-dimensional spacetime) that is analogous to classical acceleration (a three-dimensional vector, see three-acceleration in special relativity). Four-acceleration has applications in areas such as the annihilation of antiprotons, resonance of strange particles and radiation of an accelerated charge. In inertial coordinates in special relativity, four-acceleration is defined as the rate of change in four-velocity with respect to the particle's proper time along its worldline.
Accélération angulaireEn physique, l'accélération angulaire est la variation de la vitesse angulaire au cours du temps. En unités dérivées du Système international, l'accélération angulaire s'exprime en radians par seconde carrée (). L'accélération angulaire est une grandeur physique fondamentale pour caractériser le mouvement de rotation. L'accélération est la première dérivée par rapport au temps (dérivée temporelle) de la vitesse angulaire, et la seconde dérivée temporelle de la position angulaire.
Force centraleEn mécanique classique du point matériel, un champ de forces est dit champ de force centrale, de centre O s'il vérifie . Le support de la force passe par le centre fixe O. L'étude du mouvement à force centrale fut un des premiers problèmes de mécanique résolu par Newton. Si la force centrale est conservative, elle dérive d'une énergie potentielle (scalaire), notée . Souvent la constante est choisie conventionnellement, si cela est possible, pour que .
Force électromagnétiquevignette|Force de Lorentz agissant sur des particules chargées se déplaçant rapidement dans une chambre à bulles. Les trajectoires de charge positive et négative se courbent dans des directions opposées.La force électromagnétique ou force de Lorentz est la force subie par une particule chargée dans un champ électromagnétique. C'est la principale manifestation de l'interaction électromagnétique. Cette force, appliquée dans diverses situations, induit l'ensemble des interactions électriques et magnétiques observées ; elle est de ce fait principalement étudiée en physique et en chimie.
Lois de Keplerthumb|Johannes Kepler. En astronomie, les lois de Kepler décrivent les propriétés principales du mouvement des planètes autour du Soleil. L'éponyme des lois est l'astronome Johannes Kepler (-) qui les a établies de manière empirique à partir des observations et mesures de la position des planètes faites par Tycho Brahe, mesures qui étaient très précises pour l'époque ( de précision).
Schiehallion experimentThe Schiehallion experiment was an 18th-century experiment to determine the mean density of the Earth. Funded by a grant from the Royal Society, it was conducted in the summer of 1774 around the Scottish mountain of Schiehallion, Perthshire. The experiment involved measuring the tiny deflection of the vertical due to the gravitational attraction of a nearby mountain. Schiehallion was considered the ideal location after a search for candidate mountains, thanks to its isolation and almost symmetrical shape.
Gauss's law for gravityIn physics, Gauss's law for gravity, also known as Gauss's flux theorem for gravity, is a law of physics that is equivalent to Newton's law of universal gravitation. It is named after Carl Friedrich Gauss. It states that the flux (surface integral) of the gravitational field over any closed surface is proportional to the mass enclosed. Gauss's law for gravity is often more convenient to work from than Newton's law. The form of Gauss's law for gravity is mathematically similar to Gauss's law for electrostatics, one of Maxwell's equations.
Dynamique moléculaireLa dynamique moléculaire est une technique de simulation numérique permettant de modéliser l'évolution d'un système de particules au cours du temps. Elle est particulièrement utilisée en sciences des matériaux et pour l'étude des molécules organiques, des protéines, de la matière molle et des macromolécules. En pratique, la dynamique moléculaire consiste à simuler le mouvement d'un ensemble de quelques dizaines à quelques milliers de particules dans un certain environnement (température, pression, champ électromagnétique, conditions aux limites.
Static electricityStatic electricity is an imbalance of electric charges within or on the surface of a material or between materials. The charge remains until it is able to move away by means of an electric current or electrical discharge. Static electricity is named in contrast with current electricity, where the electric charge flows through an electrical conductor or space, and transmits energy. A static electric charge can be created whenever two surfaces contact and or slide against each other and then separated.
Mass in special relativityThe word "mass" has two meanings in special relativity: invariant mass (also called rest mass) is an invariant quantity which is the same for all observers in all reference frames, while the relativistic mass is dependent on the velocity of the observer. According to the concept of mass–energy equivalence, invariant mass is equivalent to rest energy, while relativistic mass is equivalent to relativistic energy (also called total energy).
Static clingStatic cling is the tendency for light objects to stick (cling) to other objects owing to static electricity. It is common in clothing, but occurs with other items, such as the tendency of dust to be attracted to, and stick to, plastic items. In clothing, static cling occurs from static electricity. An electrostatic charge builds up on clothes due to the triboelectric effect when pieces of fabric rub against each other, as happens particularly in a clothes dryer. The separate positive and negatively charged surfaces attract each other.
