IEB PHYSICS Final Exam Common Definitions

A set of vocabulary flashcards defining fundamental physical concepts, principles, and laws across kinematics, Newtonian mechanics, energy, electrostatics, electric circuits, electrodynamics, and photon phenomena.

Displacement

Change in position.

Velocity

Rate of change of displacement.

Acceleration

Rate of change of velocity.

Speed

Rate of change of distance.

Newton's Second Law

When a net force, $F_{net}$, is applied to an object of mass, $m$, the object accelerates in the direction of the net force. Acceleration is directly proportional to the net force and inversely proportional to the object's mass ($F_{net} = m a$).

Newton's Third Law

When object A exerts a force on object B, object B simultaneously exerts an oppositely directed force of equal magnitude on object A.

Universal Gravitation

Every particle with a 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 ($F = \frac{G M_1 M_2}{r^2}$).

Weight

The gravitational force the Earth exerts on any object on or near its surface.

Frictional Force

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

Gravitational Field

The force acting per unit mass.

Normal Force

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

Impulse

The product of the net force and the contact time.

Law of Conservation of Linear Momentum

The total linear momentum in an isolated system remains constant (is conserved).

Newton's Second Law in Terms of Momentum

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

Work-Energy Theorem

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

Power

The rate at which work is done OR the rate at which energy is transferred.

Law of Conservation of Energy

The total energy in a system cannot be created or destroyed, only transformed from one form to another.

Principle of Conservation of Mechanical Energy

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

Electric Field at a Point

The force per unit positive charge.

Coulomb's Law

Two point charges in free space or air exert a force on each other. The force is directly proportional to the product of their charges and inversely proportional to the square of the distance between their charges ($F = \frac{k q_1 q_2}{r^2}$).

Ohm's Law

Current through a conductor is directly proportional to the potential difference across the conductor at constant temperature.

Emf

The total energy supplied per coulomb of charge by the cell.

Current

The rate of flow of charge.

Potential Difference

The work done per unit positive charge.

Faraday's Law

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

Magnetic Flux Linkage

Product of the number of turns on the coil and the flux through the coil.

Magnetic Flux Density

A representation of the magnitude and direction of the magnetic field.

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.

Threshold Frequency ($f_0$)

The minimum frequency of incident radiation at which electrons will be emitted from a particular metal.

Work Function ($W_0$)

The minimum amount of energy needed to emit an electron from the surface of a metal.