Ferromagnetism
Ferromagnetism is the basic mechanism by which certain materials (such as iron) form permanent magnets, or are attracted to magnets. In physics, several different types of magnetism are distinguished. Ferromagnetism is the strongest type; it is the only type that can produce forces strong enough to be felt, and is responsible for the common phenomena of magnetism encountered in everyday life. One example is refrigerator magnets. The attraction between a magnet and ferromagnetic material is "the

Subatomic particle
n physics or chemistry, subatomic particles are the smaller particles composing nucleons and atoms. There are two types of subatomic particles: elementary particles, which are not made of other particles, andcomposite particles. Particle physics and nuclear physics study these particles and how they interact. [ 1 ] Elementary particles of the Standard Model include: [ 2 ] Six "flavors" of quarks: up, down, bottom, top, strange, and charm; Six types of leptons: electron, electron neutrino, muon,

Matter
Matter is a general term for the substance of which all physical objects are made. [ 1 ] [ 2 ] Typically, matter includes atoms and other particles which have mass. A common way of defining matter is as anything that has mass and occupies volume. [ 3 ] In practice however there is no single correct scientific meaning of "matter," as different fields use the term in different and sometimes incompatible ways. For much of the history of the natural sciences people have contemplated the exact natur

Nichols radiometer
A Nichols radiometer is the apparatus used by Ernest Fox Nichols and Gordon Ferrie Hull in 1901 for the measurement of radiation pressure. It consisted of a pair of small silvered glass mirrors suspended in the manner of a torsion balance by a fine quartz fibre within an enclosure in which the air pressure could be regulated. The torsion head to which the fiber was attached could be turned from the outside by means of a magnet. A beam of light was directed first on one mirror and then on the ot

PENDULUM
A pendulum is a weight suspended from a pivot so it can swing freely. [ 1 ] When a pendulum is displaced from its resting equilibrium position, it is subject to a restoring force due to gravity that will accelerate it back toward the equilibrium position. When released, the restoring force combined with the pendulum's mass causes it to oscillate about the equilibrium position, swinging back and forth. The time for one complete cycle, a left swing and a right swing, is called the period. Fro

Solid mechanics
Solid mechanics is the branch of mechanics, physics, and mathematics that concerns the behavior of solid matter under external actions (e.g., external forces, temperature changes, applied displacements, etc.). It is part of a broader study known as continuum mechanics. One of the most common practical applications of solid mechanics is the Euler-Bernoulli beam equation . Solid mechanics extensively uses tensors to describe stresses, strains, and the relationship between them. Response models A

Impulse
In classical mechanics, an impulse is defined as the integral of a force with respect to time. When a force is applied to a rigid body it changes the momentum of that body. A small force applied for a long time can produce the same momentum change as a large force applied briefly, because it is the product of the force and the time for which it is applied that is important. The impulse is equal to the change of momentum.

Hydraulics
Hydraulics is a topic in applied science and engineering dealing with the mechanical properties of liquids. Fluid mechanics provides the theoretical foundation for hydraulics, which focuses on the engineering uses of fluid properties. In fluid power, hydraulics is used for the generation, control, and transmission of power by the use of pressurized liquids. Hydraulic topics range through most science and engineering disciplines, and cover concepts such as pipe flow, dam design, fluidics and flu

HEAT
In physics and thermodynamics, heat is the process of energy transfer from one body or system due to thermal contact, which in turn is defined as an energy transfer to a body in any other way than due to work performed on the body. [ 1 ] When an infinitesimal amount of heat dQ is transferred to a body in thermal equilibrium at absolute temperature T in a reversible way, then it is given by the quantity TdS , where S is the entropy of the body. A related term is thermal energy, loosely defined a

PRESSURE
Pressure (symbol: p or P ) is the force per unit area applied in a direction perpendicular to the surface of an object. Gauge pressure is the pressure relative to the local atmospheric or ambient pressure. Definition Pressure is an effect which occurs when a force is applied on a surface. The symbol of pressure is p [ citation needed ] or P . [ 1 ] [ 2 ] Formula Conjugate variables of thermodynamics Pressure Volume (Stress) (Strain) Temperature Entropy Chem. potential Particle no. Mathematicall

Drift velocity
The drift velocity is the average velocity that a particle, such as an electron, attains due to an electric field. In general, an electron will rattle around in a conductor at the Fermi velocity randomly. An applied electric field will give this random motion a small net velocity in one direction In a semiconductor, the two main carrier scattering mechanisms are ionized impurity scattering and lattice scattering. Because current is proportional to drift velocity, which is, in turn, proportional

CHARGE
In physics, a charge may refer to one of many different quantities, such as the electric charge in electromagnetism or the color charge in quantum chromodynamics. Charges are associated with conserved quantum numbers. Formal definition More abstractly, a charge is any generator of a continuous symmetry of the physical system under study. When a physical system has a symmetry of some sort, Noether's theorem implies the existence of a conserved current. The thing that "flows" in the current i

ANTIPARTICLE
Corresponding to most kinds of particles, there is an associated antiparticle with the same mass and opposite electric charge. For example, the antiparticle of the electron is the positively charged antielectron, or positron, which is produced naturally in certain types of radioactive decay. The laws of nature are very nearly symmetrical with respect to particles and antiparticles. For example, an antiproton and a positron can form an antihydrogen atom, which has almost exactly the same propert

ACCELERATION
In physics, and more specifically kinematics, acceleration is the change in velocity over time. [ 1 ] Because velocity is a vector, it can change in two ways: a change in magnitude and/or a change in direction. In one dimension, acceleration is the rate at which something speeds up or slows down. However, as a vector quantity, acceleration is also the rate at which direction changes. [ 2 ] [ 3 ] Acceleration has the dimensions L T -2 . In SI units, acceleration is measured in metres per second

SPACE
Space is the boundless, three-dimensional extent in which objects and events occur and have relative position and direction. [1] Physical space is often conceived in three linear dimensions, although modern physicists usually consider it, with time, to be part of the boundless four-dimensional continuum known as spacetime. In mathematics spaces with different numbers of dimensions and with different underlying structures can be examined. The concept of space is considered to be of fundamental i

FORCE
In physics, force is action or agency that causes a body of mass m to accelerate. It may be experienced as a lift, a push, or a pull. The acceleration of the body is proportional to the vector sum of all forces acting on it (known as net force or resultant force). In an extended body, force may also cause rotation, deformation, or an increase in pressure for the body. Rotational effects are determined by the torques, while deformation and pressure are determined by the stresses that the forces

DENSITY
The density of a material is defined as its mass per unit volume: Different materials usually have different densities, so density is an important concept regarding buoyancy, metal purity and packaging. In some cases density is expressed as the dimensionless quantities specific gravity or relative density, in which case it is expressed in multiples of the density of some other standard material, usually water or air. History In a well known issue, Archimedes were given the task of determining w

MASS
Mass is a fundamental concept in physics, roughly corresponding to the intuitive idea of "how much matter there is in an object". Mass is a central concept of classical mechanics and related subjects, and there are several definitions of mass within the framework of relativistic kinematics (see mass in special relativity and mass in General Relativity). In the theory of relativity, the quantity invariant mass, which in concept is close to the classical idea of mass, does not vary between single

PRESSURE
Pressure (symbol: p or P ) is the force per unit area applied in a direction perpendicular to the surface of an object. Gauge pressure is the pressure relative to the local atmospheric or ambient pressure. Definition Pressure is an effect which occurs when a force is applied on a surface. The symbol of pressure is p [ citation needed ] or P . [ 1 ] [ 2 ] Formula Conjugate variables of thermodynamics Pressure Volume (Stress) (Strain) Temperature Entropy Chem. potential Particle no. Mathematicall

TORQUE
Relationship between force (F), torque (t), and momentum vectors (p and L) in a system which has rotation constrained in one plane only. (Forces and moments due to gravity and friction not shown.) Torque , also called moment or moment of force (see "Terminology" below), is the tendency of a force to rotate an object about an axis, [ 1 ] fulcrum, or pivot. Just as a force is a push or a pull, a torque can be thought of as a twist. In more basic terms, torque measures how hard something is twiste

Subtraction
Subtraction is the arithmetic operation for finding the difference between two numbers. The special names of the numbers in a subtraction expression are, minuend - subtrahend = difference. The expression 7 - 4 = 3 can be spoken as "seven minus four equals three," "seven take away four leaves three," or "four from seven leaves three." If the minuend is less than the subtrahend, the difference will be a negative number. For example, 17 - 25 = ( -8 ). We can say this as, "Seventeen minus twenty-fi

HEAT
In physics and thermodynamics, heat is energy transferred from one place in a body or thermodynamic system to another place, or beyond the boundary of one system to another one due to thermal contact even when the systems are at different temperatures. It is also often described as the process of transfer of energy between physical entities. In this description, it is an energy transfer to the body in any other way than due to work performed on the body. [ 1 ] In engineering, the discipline of

Pendulum
A gravity pendulum is a weight on the end of a rigid or flexible line or rod, which, when given some initial lift from the vertical position, will swing back and forth under the influence of gravity over its central (lowest) point. A torsion pendulum consists of a body suspended by a fine wire or elastic fiber in such a way that it executes rotational oscillations as the suspending wire or fiber twists and untwists. Gravity pendulums For small displacements, the movement of an ideal pendulum ca

FERROMAGNETISM
Ferromagnetism is the basic mechanism by which certain materials (such as iron) form permanent magnets , or are attracted to magnets. In physics, several different types of magnetism are distinguished. Ferromagnetism is the strongest type; it is the only type that can produce forces strong enough to be felt, and is responsible for the common phenomena of magnetism encountered in everyday life. One example is refrigerator magnets. The attraction between a magnet and ferromagnetic material is "th

Teacher Gifts With the Homemade Touch
Are you feeling creative or looking for a one-of-a-kind teacher gift? GreatSchools parents have some ideas for you!

ALKANE
Chemical structure of methane, the simplest alkane Alkanes, also known as paraffins, are chemical compounds that consist only of the elements carbon (C) and hydrogen (H) (i.e., hydrocarbons), wherein these atoms are linked together exclusively by single bonds (i.e., they are saturated compounds) without any cyclic structure (i.e. loops). Alkanes belong to a homologous series of organic compounds in which the members differ by a constant relative atomic mass of 14. Each carbon atom must have 4 b

CARBOHYDRATE
Lactose is a disaccharide found in milk. It is composed of a molecule of D-galactose and a molecule of D-glucose bonded by a ß-1-4 glycosidic linkage. Carbohydrates (from 'hydrates of carbon') or saccharides (Greek sά??a??? meaning "sugar") are the most abundant of the four major classes of biomolecules, which also include proteins, lipids and nucleic acids. They fill numerous roles in living things, such as the storage and transport of energy (starch, glycogen) and structural comp

SODIUM
Sodium (pronounced /ˈsoʊdiəm/ ) is an element which has the symbol Na ( Latin natrium , from Arabic natrun ), atomic number 11, atomic mass 23 amu , and a common oxidation number +1. Sodium is a soft, silvery white , highly reactive element and is a member of the alkali metals within "group 1" (formerly known as ‘group IA’). It has only one stable isotope , 23 Na. Sodium was first isolated by Sir Humphry Davy in 1807 by passing an electric current through molten sodium hydroxide

Fair and Equitable Grading Practices for Students With LD Who Have IEPs
Get guidance from an expert on how an individualized grading system may benefit your child.

Single-Sex Education: The Pros and Cons
Should boys and girls be taught separately? Does single-sex education boost academic success? Read the arguments for and against.

NITROGEN
Nitrogen is a chemical element that has the symbol N , atomic number of 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless and mostly inert diatomic gas at standard conditions , constituting 78.08% by volume of Earth's atmosphere . Many industrially important compounds, such as ammonia, nitric acid, organic nitrates (propellants and explosives ), and cyanides, contain nitrogen. The extremely strong bond in elemental nitrogen dominates nitrogen chemistry, ca

Subatomic particle
In physics or chemistry, subatomic particles are the smaller particles composing nucleons andatoms. There are two types of subatomic particles: elementary particles, which are not made of other particles, and composite particles. Particle physics and nuclear physics study these particles and how they interact. [ 1 ] Elementary particles of the Standard Model include: [ 2 ] Six "flavors" of quarks: up, down, bottom, top, strange, and charm; Six types of leptons: electron, electron neutrino, muon

Bilingual Education: Overview and Online Resources
As the debate continues over how best to teach English language learners, here are resources to help you decide what's best for your child.

Sodium hypochlorite
Sodium hypochlorite is a chemical compound with the formula NaOCl. Sodium hypochlorite solution, commonly known as bleach, is frequently used as a disinfectant or a bleaching agent. Production Hypochlorite was first produced in 1789 by Claude Louis Berthollet in his laboratory on the quay Javel in Paris, France, by passing chlorine gas through a solution of sodium carbonate. The resulting liquid, known as " Eau de Javel " ("Javel water"), was a weak solution of sodium hypochlorite. However, thi

AMIDE
In chemistry, amide usually refers to organic compounds that contain the functional group consisting of an acyl group (C=O) linked to a nitrogen atom (N). The term refers both to a class of compounds and a functional group within those compounds. The term amide also refers to deprotonated form of ammonia (NH 3 ) or an amine, often represented as anions R 2 N - . The remainder of this article is about the carbonyl-nitrogen sense of amide . For discussion of these "anionic amides," see the articl

Section 504 updated: Greater eligibility and accommodations for students with LD, AD/HD
Learn about recent improvements made to Section 504, a civil rights law that now provides protection and accommodations to even more students with LD and/or AD/HD.

Vector calculus identities
Single operators (summary) This section explicitly lists what some symbols mean for clarity. Divergence Divergence of a vector field For a vector field , divergence is generally written as and is a scalar . Divergence of a tensor For a tensor , divergence is generally written as and is a vector. Curl For a vector field , curl is generally written as and is a vector field. Gradient Gradient of a vector field For a vector field , gradient is generally written as and is a tensor. Gradient of a sca

Strategies for Managing Your Child's Resistant Behavior
An expert explains how to manage resistance by identifying the purpose a behavior serves for a child.

CHARGE
In physics, a charge may refer to one of many different quantities, such as the electric charge in electromagnetism or the color charge in quantum chromodynamics. Charges are associated with conserved quantum numbers. Formal definition More abstractly, a charge is any generator of a continuous symmetry of the physical system under study. When a physical system has a symmetry of some sort, Noether's theorem implies the existence of a conserved current. The thing that "flows" in the current i

My Child Won't Talk at School
How to talk to your child about events with no easy explanation.