All Physics definitions

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Newtons Law of universal gravitation

Every particle with mass in the universe attracts every other particle with a force which is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centres.

Weight (gravitation force)

The force of attraction exerted by a planet acting on an object.

Gravitational field

a force experienced per unit of mass.

Electric charge

the physical property of matter that causes it to experience a force when placed in an electromagnetic field.

DESCRIBE an electric field

A region in space where another electric charge will Experience a force.

DEFINE an electric field

As the force experienced per unit positive charge (+1C)at that point.

Coulombs Law

Two point charges in free space or in air exert forces on eachother. The force between two charges is directly proportional to the product of the charges and inversely proportional to the distance between the charges squared.

Cycle

One complete oscillation

Medium

Substance or material through which a wave moves ( or through which energy is transferred )

Pulse

A single vibration or disturbance or oscillation . It is one complete to and fro cycle of a vibrating system .

wave

A wave is a disturbance that is repeated regularly as it travels through a medium or through space , transporting energy from one place to another , without transporting matter . A wave differs from a pulse in that it is caused by regular vibrations at its source , and a pulse is caused by a single disturbance .

Position of rest or equilibrium position

The resting position in waves is the undisturbed position of the medium , also known as the equilibrium position.

Crest

a point on a wave where the displacement of the medium is at a maximum .

trough

a point on a wave where the displacement of the medium is at a minimum.

Rarefaction

A rarefaction is a region in a longitudinal wave where the particles are furthest apart .

Compression

A compression is a region in a longitudinal wave where the particles are closest together

Amplitude

Maximum displacement of the particles of the medium from their position of rest . It is the height of a crest or the depth of a trough measured from the resting ( or equilibrium ) position . ( Amplitude is measured in metres )

points in phase

Two particles are in - phase when they move simultaneously in exactly the same direction and with the same speed as each other .

wavelength

one wavelength is the distance between two consecutive points on the wave that are in phase.

Scalar

as a physical quantity with magnitude only

Vector

as a physical quantity with magnitude and direction

Position

relative to a reference point

Distance

the length of the path travelled .

Displacement

the change in position from the initial to the final position

speed

the rate of change of distance

velocity

the rate of displacement

Acceleration

the rate of change of velocity

Electric current

the rate of flow of charge

Potential difference

Is the work done per unit positive charge

Power

The rate at which work is done

Ohms law

the current through a conductor between two points is directly proportional to the potential difference across a conductor at constant temperature

resultant vector

The single vector which has the same effect as the original vectors acting together.

Triangular Law of Forces

Three forces in equilibrium can be represented by the three sides of a closed triangle taken in order (head to tail)

normal force

The perpendicular force exerted by a surface on an object in contact with it

Frictional Force

The force that opposes the motion of an object

Newton's First Law

Any object continues in a state of rest or uniform velocity unless it's acted upon by a net or resultant force

Inertia

The property if an object that causes it to resist a charge in its state of rest or uniform motion

Newton's Second Law

When a net force is applied to an object with mass the object accelerates in the direction of net force. The acceleration is directly proportional to the net force and inversely proportional to the mass

Frictional force due to a surface

Is the force that opposes the motion of an object (and acts parallel to the surface with which the object is in contact)

Newton's Third Law

When object A exerts a force on object B, object B simultaneously exerts an equal and opposite force on object A

terminal velocity

The maximum velocity attained by an object which has a constant applied force acting on it while moving through a frictional medium

resistance

A material's opposition to the flow of electric current.

EMF

The total energy supplied per coulomb of charge by the cell

Component

One of the vectors of two or more vectors which when added together give one the original vector

Linear Momentum

The product of the mass and velocity of an object

Newtons 2 according to momentum

The net force of an object is equal to the rate of change of momentum of an object

Law of conservation of linear momentum

The total linear momentum of an object in an isolated system remains constant

Elastic collision

A collision is which both momentum and kinetic energy are conserved

Inelastic collision

A collision in which only momentum is conserved

Impulse

The product of the net force and the contact time

Work done on an object by a force

the product of the displacement and the component of the force parallel to the displacement

Gravitational potential energy

The energy an object possesses due to its position relative to a reference point

Kinetic energy

The energy that an object has as a result of the objects motion

Mechanical energy

The sum of the gravitational potential energy and the kinetic energy at a point

Work energy theorem

The work done by a net force on an object is equal to the change in kinetic energy of an object

power

The rate at which work is done

Efficiency

The ration of the output power to input power

Isolated system

a system that has no net external force acting on it

Energy

Energy is the ability to do work

The principle of conservation of mechanical energy

In the absence of air resistance or any external forces, the mechanical energy of an object is constant

magnetic flux linkage

the product of the number of turns on the coil and the flux through the coil

Faraday's law of electromagnetic induction

the emf induced is directly proportional to the rate of change of magnetic flux ( flux linkage )

Diode

A component that only allows current to flow in one direction

Lenz's law

the induced current flows in a direction so as to set up a magnetic field to oppose the change in magnetic flux

Magnetic flux

The total number of magnetic field lines through an area