Cambridge IGCSE Physics 0625 Complete A* Study Notes

A set of flashcards covering key vocabulary and definitions from the Cambridge IGCSE Physics syllabus.

Scalar Quantity

A quantity that has magnitude (size) only — no direction.

Vector Quantity

A quantity that has both magnitude and direction.

Speed (v)

Distance travelled per unit time, expressed as v = s / t (m/s).

Velocity

Speed in a given direction (vector quantity).

Acceleration (a)

The change in velocity per unit time, expressed as a = Δv / Δt (m/s²).

Newton's 1st Law

An object remains at rest or in uniform motion unless acted upon by a resultant force.

Weight (W)

The gravitational force acting on an object, defined by W = mg (N).

Density (ρ)

Mass per unit volume, defined as ρ = m / V (kg/m³ or g/cm³).

Momentum (p)

Mass times velocity, expressed as p = mv (kg m/s).

Work Done (W)

The energy transferred when a force moves an object, defined as W = Fd (J).

Power (P)

The rate of doing work or energy transfer, expressed as P = W/t (W).

Pressure (p)

Force per unit area, defined as p = F / A (Pa = N/m²).

Energy Conservation Principle

Energy cannot be created or destroyed, only transferred or transformed.

Kinetic Energy Equation

E_k = (1/2)mv²; represents kinetic energy of an object in motion.

Specific Heat Capacity (c)

The energy required to raise the temperature of 1 kg of a substance by 1 °C, expressed in J/(kg °C).

Boyle's Law

For a fixed mass of gas at constant temperature, the product of pressure and volume is constant (pV = constant).

Total Internal Reflection (TIR)

Occurs when the angle of incidence exceeds the critical angle in a denser medium, causing all light to reflect back.

Electromagnetic Spectrum Order

The range of all EM radiation types, ordered from low to high frequency: Radio, Microwave, Infrared, Visible Light, Ultraviolet, X-rays, Gamma rays.

Evaporation vs Boiling

Evaporation occurs at the surface at any temperature; boiling occurs throughout the liquid at its boiling point.

Brownian Motion

Random motion of microscopic particles caused by collisions with fast-moving molecules; evidence for the kinetic particle model.

Terminal Velocity

The constant speed reached by an object when the force of gravity is balanced by the drag force.