H2 Physics – Master Vocabulary List

Vocabulary flashcards covering the key physics concepts, laws, and definitions from the H2 lecture notes.

Systematic Error

systematic error have the same magnitude and sign when measurements are repeated 

Random Error

random errors have different magnitude and signs when measurements are repeated.

Accuracy

how close a measured value is to the true value

Precision

how close the repeated measurements are to each other, without regard to the true value

Base Units

Fundamental units from which all other units are derived.

Derived Units

Units expressed as products or quotients of base units.

Scalar Quantity

Physical quantity with magnitude only, no direction.

Vector Quantity

Physical quantity possessing both magnitude and direction.

Distance

Total length travelled irrespective of direction.

Speed

Rate of change of distance travelled per unit time.

Displacement

shortest linear distance of the position of a moving object from a given reference point

Velocity

Rate of change of displacement.

Acceleration

Rate of change of velocity.

Equation of Motion 1

v = u + at (constant acceleration, straight-line motion).

Equation of Motion 2

s = ½(u + v)t (area under velocity-time graph).

Equation of Motion 3

v² = u² + 2as (derived from Eqs. 1 & 2).

Equation of Motion 4

s = ut + ½at² (derived from Eqs. 1 & 2).

Field of Force

Region where a force is experienced by an appropriate test particle.

Gravitational Field

Region where a mass experiences an attractive force due to another mass.

Electric Field

Region where an electric charge experiences an electric force.

Magnetic Field

Region where a moving charge or current experiences a force perpendicular to the field.

Hooke’s Law

Extension of a spring is proportional to applied force, provided the limit of proportionality is not exceeded.

Static Equilibrium Conditions

Resultant force = 0 and resultant moment about any point = 0.

Principle of Moments

Sum of anticlockwise moments about a point equals sum of clockwise moments about that point.

Moment of a Force

Product of force and perpendicular distance from pivot.

Torque of a Couple

One force of the couple × perpendicular distance between the forces.

Couple

Pair of equal and opposite forces whose lines of action do not coincide; produces rotation only.

Centre of Gravity

Point through which the entire weight of an object appears to act.

Hydrostatic Pressure

p = ρgh, pressure at depth h in a fluid of density ρ.

Upthrust

Upward force on an object in a fluid equal to weight of fluid displaced.

Flotation Principle

An object floats when upthrust equals its weight.

Newton’s First Law

Body remains at rest or in uniform straight-line motion unless acted on by a net external force.

Newton’s Second Law

Rate of change of momentum is proportional to net force and in its direction.

Newton’s Third Law

For every action, there is an equal and opposite reaction on a different body.

Linear Momentum

Product of mass and velocity of a body.

Impulse

Product of force and the time interval during which it acts.

Conservation of Momentum

Total momentum of a system remains constant if no external force acts.

Mass

Measure of a body's inertia (resistance to change in motion).

Weight

Force experienced by a mass in a gravitational field; W = mg.

Apparent Weightlessness

Condition when normal reaction on a body is zero because it accelerates at g.

Work (Constant Force)

Product of constant force and displacement in direction of force.

Energy

Ability to do work; appears in many forms such as kinetic, potential, thermal, etc.

Potential Energy

Stored energy available to do work.

Conservation of Energy

Total energy of an isolated system is constant; energy is neither created nor destroyed.

Gravitational Potential Energy

Energy a mass possesses due to its position in a gravitational field; GPE = mgh (near Earth’s surface).

Elastic Potential Energy

Energy stored due to deformation (stretching or compression).

Kinetic Energy Formula

KE = ½mv².

Power

Work done per unit time.

Power Formula

P = Fv, instantaneous power delivered by force F at velocity v.

Angular Displacement

Angle (in radians) through which a body rotates about a centre.

Radian

Angle subtended at circle’s centre by an arc equal in length to the radius.

Angular Velocity

Rate of change of angular displacement; ω = dθ/dt.

Tangential Velocity

Instantaneous linear velocity along circular path; v = rω.

Centripetal Force

Resultant force directed toward centre required for circular motion.

Geostationary Satellite

Satellite that remains above the same point on Earth’s equator by orbiting once every 24 h west-to-east.

Newton’s Law of Gravitation

Gravitational force ∝ product of masses and inversely ∝ square of separation.

Gravitational Field Strength

Force per unit mass at a point; g = F/m.

Gravitational Potential

Work done per unit mass by external agent moving mass from infinity to the point without KE change.

Simple Harmonic Motion

Oscillation where acceleration is proportional and opposite to displacement from equilibrium.

Damping

Loss of energy from an oscillating system due to dissipative forces like friction.

Resonance

Maximum amplitude response when driving frequency equals natural frequency of a system.

Progressive Wave

Disturbance that transfers energy from source to surrounding points by particle oscillations.

Transverse Wave

Wave with particle oscillations perpendicular to direction of propagation.

Longitudinal Wave

Wave with particle oscillations parallel to direction of propagation.

Wavelength

Distance between two consecutive points in phase on a wave.

Wave Speed

Speed at which wave energy propagates; v = fλ.

Intensity (Wave)

Rate of energy flow per unit cross-sectional area perpendicular to propagation.

Polarisation

Process restricting wave oscillations to one direction in the plane normal to propagation.

Malus’ Law

Transmitted light intensity I ∝ cos²θ between analyser and polariser axes.

Diffraction

Spreading of waves into region behind an obstacle or through a gap.

Principle of Superposition

Resultant displacement at a point equals vector sum of individual wave displacements.

Coherent Waves

Waves maintaining constant phase difference over time.

Constructive Interference

Superposition where waves meet in phase, producing maximum amplitude.

Destructive Interference

Superposition where waves meet in antiphase (π rad), producing minimum amplitude.

Rayleigh Criterion

Two images are just resolved when central maximum of one coincides with first minimum of the other.

Stationary (Standing) Wave

Wave pattern with fixed nodes and antinodes; no net energy transport.

Node

Point on standing wave with permanent zero displacement.

Antinode

Point on standing wave where amplitude is maximum.

Thermal Equilibrium

State where no net heat flow occurs between objects.

Absolute Temperature Scale

Temperature scale independent of substance properties; zero at minimum internal energy.

Avogadro Constant

Number of particles in one mole: 6.02 × 10²³ mol⁻¹.

Mole

Amount of substance containing as many entities as atoms in 0.012 kg of carbon-12.

Ideal Gas

Gas obeying pV = nRT for all pressures, volumes, and temperatures.

Specific Heat Capacity

Energy required to raise temperature of unit mass of a substance by 1 K without phase change.

Specific Latent Heat of Vaporization

Energy per unit mass to change liquid to gas at constant temperature.

Specific Latent Heat of Fusion

Energy per unit mass to change solid to liquid at constant temperature.

Internal Energy

Sum of microscopic kinetic and potential energies of a substance’s molecules.

First Law of Thermodynamics

Increase in internal energy = heat supplied + work done on system.

Electric Current

Rate of flow of charge; I = ΔQ/Δt.

Drift-Velocity Formula

I = nAvq, where n is carrier density, A cross-section, v drift speed, q charge.

Electromotive Force (emf)

Energy converted from other forms to electrical per unit charge by a source around a circuit.

Potential Difference

Energy converted from electrical to other forms per unit charge between two points.

Resistance

Ratio of potential difference across a component to current through it; R = V/I.

Resistivity

Resistance of material of unit length and unit cross-sectional area.

Light-Dependent Resistor (LDR)

Semiconductor whose resistance decreases as incident light intensity increases.

NTC Thermistor

Semiconductor whose resistance decreases with increasing temperature.

Electric Field

Region where a charge experiences electric force.

Coulomb’s Law

Electric force between two point charges ∝ product of charges and inversely ∝ square of separation.

Electric Field Strength

Electric force per unit positive test charge; E = F/q.

Equipotential Surface

Surface of constant electric potential; no work is done moving charge along it.