Important Terms and their Definitions of Physics
- Acceleration: The rate of change of velocity of an object with
respect to time.
- Angular Momentum: A measure of the momentum of a body in
rotational motion about its center of mass.
- Alloy: The mixture of metal with other
metal or other elements.
- Ammeter: An instrument that is used to measure current.
- Amorphous solid: It’s a type of solid which does not have definite
geometrical shape, or its non-crystalline solid.
- Ampere: A unit that describes the rate of flow of electricity
(current).
- Amplifier: It is an electronic device that can increase the power
of a signal (a time-varying voltage or current).
- Amplitude: Height of a wave measured from its center (normal)
position.
- Alpha particle: Consist of two protons and two neutrons bound together
into a particle identical to a helium nucleus, which is classically produced in
the process of alpha decay, but may be produced also in other ways and given
the same name.
- Astronomical unit: It is a unit of length, roughly the
distance from Earth to the Sun.
- Astrophysics: The branch of astronomy that deals with the physics of
the universe
- Atom: A basic unit of matter that consists of a dense central nucleus
surrounded by a cloud of negatively charged electrons. The atomic nucleus
contains a mix of positively charged protons and electrically neutral neutrons.
- Atomic mass unit (a.m.u): One-twelfth the mass of an atom of the
isotope 12⁄6C.
- Avogadro's number: The number of molecules in exactly 12g of carbon-12,
equaling 6.022 x 1023.
- Battery: Battery is combination of two or more cells (electric),
which produces electricity.
- Beam: A structural element that is capable of withstanding load primarily by
resisting bending.
- Beta particle: High-energy, high-speed electrons or positrons emitted
by certain types of radioactive nuclei.
- Biophysics: An interdisciplinary science using methods of, and
theories from, physics to study biological systems.
- Black hole: A region of space-time where gravity prevents anything,
including light, from escaping.
- Coulomb: The SI derived unit of electric charge. It is defined
as the charge transported by a steady current of one ampere in one second.
- Collision: A collision in physics occurs when any two objects bump
into each other.
- Classical: A sub-field of mechanics that is concerned with the set
of physical laws describing the motion of bodies under mechanics the action of
a system of forces.
- Celsius scale: A scale and unit of measurement for temperature, also
known as Centigrade.
- Center of gravity: The point in a body around which the resultant torque
due to gravity forces vanish. Near the surface of the earth, where the gravity
acts downward as a parallel force field, the center of gravity and the center
of mass are the same.
- Center of mass: A distribution of mass in space is the unique point where
the weighted relative position of the distributed mass sums to zero.
- Convection: The transfer of heat by the actual transfer of matter.
- Cyclotron: A type of particle accelerator in which charged
particles accelerate outwards from the center along a spiral path.
- Density: The mass density or density of a material is its mass
per unit volume. Mathematically, density is defined as mass divided by volume.
- Distance: A numerical description of how far apart objects are.
- Displacement: In physics, displacement refers to an object's overall
change in position. It is a vector quantity.
- Elasticity: A physical property of materials which return to their
original shape after they are deformed.
- Electric charge: A physical property of matter that causes it to
experience a force when near other electrically charged matter. There exist two
types of electric charges, called positive and negative.
- Electric circuit: An electrical network consisting of a closed loop,
giving a return path for the current.
- Electric current: A flow of electric charge through a conductive medium.
- Electric field: The region of space surrounding electrically charged
particles and time-varying magnetic fields.
- Electric power: The rate at which electric energy is transferred by an
electric circuit.
- Electronics: A field that deals with electrical circuits that
involve active electrical components such as vacuum tubes, transistors, diodes
and integrated circuits, and associated passive interconnection technologies.
- Energy: Energy is the ability to do work. The standard unit of
measure for energy is the joule.
- Entropy: A quantity which describes the randomness of a substance
or system.
- First law of motion: The first law of motion states that any object in
motion will continue to move in the same direction and speed unless external
forces act on it.
- Force: Force is the measurement of a push or pull on an object. Force is a
vector measured in Newton’s.
- Friction: Friction is the resistance of motion when one object
rubs against another. It is a force and is measured in Newton’s.
- Fusion: A nuclear reaction in which two or more atomic nuclei
join together, or "fuse", to form a single heavier nucleus.
- Gravity: Gravity is a force caused when the mass of physical
bodies attract each other. On Earth gravity pulls at objects with an
acceleration of 9.8 m/s2.
- Gamma ray: Electromagnetic radiation of high frequency and
therefore high energy.
- Impulse: An impulse is a change in momentum.
- Heat (or heat transfer/heat flow): Energy
transferred from one body to another by thermal interaction.
- Ion: An atom or molecule in which the total number of electrons is not equal
to the total number of protons, giving the atom a net positive or negative
electrical charge.
- Ionic bond: A type of chemical bond formed through an electrostatic
attraction between two oppositely charged ions.
- Ionization: The process of converting an atom or molecule into an
ion by adding or removing charged particles such as electrons or ions.
- Isotope: Variants of a particular chemical element. While all
isotopes of a given element share the same number of protons, each isotope
differs from the others in its number of neutrons.
- Joule: The joule is the standard unit of measure for energy and work.
- Kelvin: A unit of measurement for temperature. The Kelvin scale
is an absolute, thermodynamic temperature scale using as its null point
absolute zero.
- Kinetic energy: Kinetic energy is the energy an object has due to its
motion. It is a scalar quantity calculated using the formula
- KE = ½ * m * v2, where m = mass and v = velocity.
- Light: Visible light (commonly referred to simply as light) is electromagnetic radiation that is visible to the human eye, and is responsible for the sense of sight.
- Magnetic field: A mathematical
description of the magnetic influence of electric currents and magnetic
materials. The magnetic field at any given point is specified by both a
direction and a magnitude (or strength); as such it is a vector field.
- Magnetism: A property of materials that respond
to an applied magnetic field.
- Mass balance: An application of conservation of mass
to the analysis of physical systems, also called 'material balance'.
- Mass density: A materials mass per unit volume, also
just called density.
- Molar mass: A physical property of matter. It is
defined as the mass of a given substance divided by its amount of substance. The
unit for molar mass is g/mol.
- Molecule: An electrically neutral group of two
or more atoms held together by covalent chemical bonds.
- Momentum: Momentum is a measurement of mass in
motion. Momentum is equal to the mass times the velocity of an object. It is a vector measured in Newton’s-seconds.
- Nano Technology: The manipulation of matter on an
atomic and molecular scale.
- Neutrino: An electrically neutral subatomic
particle.
- Nuclear physics: The field of physics that studies the
constituents and interactions of atomic nuclei.
- Newton: The Newton is the standard unit of
measure for force.
- Optics: The branch of physics which involves
the behavior and properties of light, including its interactions with matter and
the construction of instruments that use or detect it.
- Ohm: The SI derived unit of electrical resistance.
- Pascal: The Pascal is the standard unit of
measure for pressure.
- Photon: An elementary particle, the quantum
of light and all other forms of electromagnetic radiation, and the force carrier
for the electromagnetic force.
- Potential energy: Potential energy is the energy stored
by an object due to its state or position. It is measured in joules.
- Physics: it is the general analysis of nature,
conducted in order to understand how the universe behaves.
- Power: Power is a measurement of the rate at which energy is
used. Power is calculated by dividing work over time. The standard unit for
power is the watt.
- Power (electric): The rate at which electric energy is
transferred by an electric circuit.
- Pressure: The ratio of force to the area over
which that force is distributed.
- Probability: A measure of the expectation that an
event will occur or a statement is true.
- Pressure: Pressure is the force over a given
area. Pressure is measured in pascals.
- Quark: An elementary particle and a fundamental constituent of
matter.
- Quantum mechanics: A branch of physics dealing with
physical phenomena at microscopic scales, where the action is on the order of the
Planck constant.
- Refraction: Refraction is the change in direction
of wave propagation due to a change in its transmission medium.
- Rotational energy: (or angular kinetic energy) The
kinetic energy due to the rotation of an object and forms part of its total
kinetic energy.
- Scalar: A scalar is a measurement that only
measures the magnitude. Unlike a vector, a scalar does not have direction.
- Speed: Speed is the measurement of how fast on object moves
relative to a reference point. It is a scalar quantity measured by distance
over time.
- Science: A systematic enterprise that builds
and organizes knowledge in the form of testable explanations and predictions about
the universe.
- Sound :
A mechanical wave that is an oscillation of pressure transmitted through a
solid, liquid, or gas, composed of frequencies within the range of hearing.
- Superconductor: A phenomenon of exactly zero
electrical resistance and expulsion of magnetic fields occurring in certain materials
when cooled below a characteristic critical temperature.
- Temperature: A physical property of matter that
quantitatively expresses the common notions of hot and cold.
- Vector: A vector is a quantity that has both
a magnitude and a direction.
- Velocity: Velocity is the rate of change in an
object's position. Velocity is a vector quantity. The magnitude of velocity is the
object's speed.
- Wave: A disturbance or oscillation that travels through space-time,
accompanied by a transfer of energy.
- Wavelength: The wavelength of a sinusoidal wave
is the spatial period of the wave.
- Wind: The flow of gases on a large scale.
- X Ray: A high energy photon (between 100 electron volts (eV)
and 100 keV),
- Young’s modulus: A measure of the stiffness of a solid
material which defines the relationship between stress and strain
- Zeeman Effect: The effect of splitting a spectral line into several components in the presence of a static magnetic field by the lifting of degeneracy in electronic states.