Static electricity and electric fields
A lesson introducing charge as a fundamental property of matter; electrostatic forces of attraction & repulsion; electric fields around point charges; charging by friction; the phenomenon of static electricity.
Current, potential difference and resistance
Definition & explanation of electric current and how it relates to charge; conditions required for current flow & concept of potential difference; relationship between current, p.d. and resistance (Ohm’s Law).
Standard symbols for electrical circuit components; series & parallel circuit diagrams; I-V graphs for Ohmic & non-Ohmic resistors; behaviour of current, p.d. and resistance in series & parallel circuits.
Electrical Energy Transfers
General definition of power and application to electrical circuits; calculation of cost of electrical power (kWh); using equations to calculate p.d., current, resistance, power, work done and time in circuits.
The National Grid
National Grid as a system of cables and transformers linking power stations to consumers which is used to transfer electrical power; use of step-up & step-down transformers allowing efficient transfer of power.
Domestic uses and safety
Direct vs. alternating p.d.; colours & functions of live, neutral & earth wires in three-core cables of mains supply; hazards of mains electricity, safety devices & precautions (earthed casings, RCD’s & fuses).
Kinetic Theory of Matter
The ‘Particle Model’
The characteristic properties of solids, liquids and gases in terms of the arrangements, motion and attractive forces between particles; the definition, calculation & experimental determination of density.
Temperature & the Gas Laws
Definition of temperature & its scales; gas pressure in terms of particle motion; Boyle’s Law; Charles’ Law; Gay-Lussac’s Law; the “Combined” Gas Law; calculation of pressure, volume or temperature of gases.
Temperature, internal energy and heat
Definition and distinction between the terms temperature, internal energy, thermal energy and heat; variation in these quantities under heating and cooling, and how these quantities relate to particle motion.
Thermal energy transfers
Thermal energy transfer by conduction, convection & infrared radiation; explanation of these modes of thermal energy transfer in terms of changes in kinetic energies of particles, internal energy & heat transfer.
Heating and cooling
Definition and calculation of specific heat capacity; how internal energy is altered by heating and cooling; distinction between changes in temperature and changes of state in terms of heat energy transfers.
Changes of state
Explanation of changes of state in terms of heat transfer, particle motion & attractive forces between particles; definition & calculation of specific latent heat and heat energy transfer during changes of state.
Heating & Insulating Buildings
Distinction between a thermal conductor and a thermal insulator; thermal conductivity of various materials in terms of the particle model; applying the particle model to explain thermal insulation of buildings.
Pressure and gases
How the motion of the molecules in a gas is related both to its temperature and its pressure; work done on/by gases and relationship to gas pressure, volume & temperature; explanation of atmospheric pressure.
Development of the atomic model
How and why the atomic model has changed over time; basic structure of atoms in terms of sub-atomic particles (protons, neutrons and electrons), including their relative charges, masses and arrangement in atoms.
Atoms and isotopes
Differences between atoms of different elements & between isotopes of an element; definitions of atomic number, mass number & relative atomic mass; typical size & scale of atoms & molecules (orders of magnitude).
Concept of nuclear instability and emission of nuclear radiation by unstable nuclei; standard symbols for alpha, beta and gamma emissions and use of nuclear decay equations; concept of half-life & its application.
Types of nuclear radiation
Standard notation and balanced nuclear decay equations for alpha, beta & gamma emission; ionisation of atoms by alpha, beta and gamma radiation; penetrating & ionising powers of these types of nuclear radiation.
Hazards & applications
Differences between nuclear contamination and irradiation hazards; how hazards nuclear materials differ with half-life & type of emission; applications of nuclear radiation (e.g. in medical & industrial contexts).
Fission in terms of inducing increased nuclear instability through neutron absorption; nuclear chain reactions; description of fission using nuclear equations; generating electrical power in nuclear reactors.
Fusion in terms of combination of smaller nuclei to form more stable larger nuclei; conditions for nuclear fusion; description of fission using nuclear equations; conversion of mass to energy during fusion reactions.
Resultant Force & Newton’s Laws
Concepts of force, resultant force and the effects of forces on objects in both qualitative and quantitative terms; Newton’s Laws of motion; forces as vector quantities; resolution & summation of force vectors.
Work done by forces
Relationships between work, force, & displacement, and the energy transfer involved; distinction between internal & external work, and between positive & negative work, and how these affect energy stored in systems.
Moments, gears & levers
Definition of the moment of a force and its calculation, including for forces at angles other than perpendicular to objects; types of gears & transmission of moments of forces by gears, to include gear ratios.
Gravity & centre of mass
Gravitational fields as field phenomena around masses causing attractive forces affecting other masses, and dependency of field strength on mass; definition of weight and its calculation near the surface of Earth.
Forces & elasticity
Hooke’s Law & elastic potential energy, and the dependency of the latter on work done by forces in elastic deformation of objects; definition of spring constant in linear cases; elastic vs plastic deformation.
Speed, distance & time
Vector/scalar distinction as applied to distance and displacement; calculation of average speed for non-uniform motion; distance-time graphs; conversion between standard (SI) & non-standard units of speed.
Velocity & acceleration
The vector/scalar distinction as it applies to velocity and speed; velocity vs. time graphs (including interpreting slopes & enclosed area under such graphs); the definition & calculation of acceleration.
Equations for constant acceleration
Calculation of acceleration given appropriate velocity, displacement, and time data using “VUSTA” equations for constant (uniform) acceleration; numerous examples of use of equations for constant acceleration.
A lesson outlining examples of the forces acting on an isolated solid object or system (including examples of objects that reach terminal velocity for example skydivers and applying similar ideas to vehicles).
Inertia as a measure of how difficult it is to change the velocity of an object; mass defined as the ratio of force over acceleration; definition of momentum; elastic collisions; law of conservation of momentum.
Forces and vehicle safety
Factors affecting vehicle safety; stopping distance, thinking distance & braking distance, and the factors affecting these in terms of forces, momentum, impulse & acceleration; measurement of reaction times.
Explanation of why an object moving in a circular path at constant speed has a changing velocity (and is therefore accelerating) & requirement for resultant (centripetal) force towards centre of the circular path.
Properties of a pendulum; the relationships between length, amplitude, frequency & period of oscillation of a pendulum; transfer of gravitational potential energy to kinetic energy during motion of a pendulum.
Pressure in liquids
Explanation of pressure in liquids and its dependency on depth, gravitational field strength and density of liquid; factors affecting floating & sinking; calculation of pressure differences at different depths; hydraulics.
General properties of waves
Waves as oscillatory phenomena which transfer energy; categorisation of waves (longitudinal vs. transverse); definitions & relationships between amplitude, wavelength, frequency, time period & speed.
Sound as longitudinal waves in matter; variation in velocity, frequency & wavelength in transmission of sound waves from one medium to another; perceived qualities of sound vs. frequency, wavelength, amplitude.
Effects of reflection, transmission, and absorption of ultrasound at material interfaces; applications of ultrasound (medical & industrial); including calculating distances between material interfaces from ultrasound probe data.
Seismic Waves & Earthquakes
The detection of earthquakes and other geological events by means of seismic waves (L, R, P & S-waves), including the features of seismic waves and how they are used in exploration of the Earth’s structure.
EM waves, light and its applications
EM waves as transverse waves in electric & magnetic fields; parts of EM spectrum (ranges of wavelength & frequency); colour as differential absorption, reflection & transmission of visible light; specular reflection & scattering.
Reflection & mirrors
Law of reflection; using ray diagrams to illustrate reflection at plane & curved (convex & concave mirror) surfaces, including production of real & virtual images, positions & sizes of objects & images relative to reflecting surface.
Refraction & lenses
Explanation of refraction in terms of changes in velocity of EM waves in different media; using ray diagrams to illustrate refraction at material boundaries (including convex & concave lenses and their uses in correction of vision).
Parts of the mammalian eye and their functions, with specific reference to the role of refraction in the functions of the cornea and lens in focussing vision; eye defects and their correction using convex or concave lenses in more depth.
Dependency of intensity & wavelength of EM radiated on temperature & explanation of how the temperature of a body is related to the balance between incoming radiation absorbed and radiation emitted; examples to illustrate.
UV Light & Ozone
Emission of ultraviolet light and its interaction with the ozone layer; role of the ozone layer in protecting living organisms from harmful effects of ultraviolet EM waves, and an overview and explanation of these harmful effects.
Properties of X-Rays (including the inverse square law and absorption & emission); differences in absorption, velocity & reflection of X-rays used for detection & imaging of structures in the body; applications in the medical context.
Radio & Microwaves (Communication & Heating)
Connection between radio wave emission & absorption and oscillations of electrical current; how radio waves & microwaves are used in communications; explanation of use of microwaves in heating (microwave ovens etc.).
Magnetism & Electromagnetism
Magnets and magnetic fields
Description & explanation of magnetic fields as fields of force around magnetic objects; poles of magnets and forces of attraction/repulsion; explanation of magnetic field of Earth and behaviour of magnetic compass.
The motor effect
Relationship between electric current & magnetic field; Fleming’s left-hand rule; force on conductor, magnetic field strength, length of conductor & current; dependency of strength of field on distance from conductor.
The generator effect
Explain how a change in the magnetic field around a conductor causes an induced p.d., generating a magnetic field that would oppose the original change; application to a.c. generator & d.c. dynamo.
Explanation of the structure & operation of transformers in terms input/output voltage and primary/secondary coils, current, etc.; applications of principles of electromagnetic induction to microphones & loudspeakers.
Astronomy, Astrophysics & Cosmology
Our solar system
Formation of the solar system; Similarities & distinctions between the planets, their moons & artificial satellites; Formation of the Sun (gravitational attraction, fusion reactions & the balance between these forces).
Stars and their “life-cycles”
The possible stages in the “life-cycles” of stars; importance of fusion reactions & gravitational collapse; possible changes in structure of stars & dependence on mass of star (including giants/dwarves, supernovae etc.).
Redshift & the origin of the universe
Red-shift in terms of changes in frequency/wavelength; relationship between red-shift & speed of recession of galaxies; Evidence for “Big Bang” cosmological model (red-shift & microwave background radiation).
Defining and categorising energy
The concept of energy as a mathematical abstraction given meaning through calculation, the categorisation of energy stored in systems as kinetic or potential, and the definition of these terms; transfer of energy as work.
Work & the conservation of energy
Work defined as change in the total energy stored in a system; Defining and categorising work as internal vs. external (external work as positive or negative); conservation of energy in terms of internal/external work.
Mechanical Kinetic Energy
Redistribution of energy in a system when work is done by forces; work defined as the product of force and parallel displacement; calculation of work, potential & kinetic energy in systems using appropriate equations.
Elastic Potential Energy
Definition of elastic potential energy stored in objects under elastic deformation (extension & compression) by forces, in terms of force, work done, extension/compression and spring constant; examples of calculations.
Gravitational Potential Energy
Potential energy arising as a result of the ability of fields to do work by exerting forces at a distance; gravitational fields; calculations of gravitational potential energy, kinetic energy & work done by gravity.
Solving Mechanics Problems With Energy
In this lesson we bring together the ideas from the previous lessons in this topic to easily solve what would otherwise be complex problems in mechanics involving systems undergoing changes.
Internal Energy & Heat
Changes in energy involved when a system is changed by heating in terms of temperature change, specific heat capacity, mass and changes in the thermal energy of the system (i.e. change in internal energy of the object).
In this lesson we explore the application of the concept of energy to electrical systems; the electrical potential energy of charged objects in electric fields & the energy transferred by an electric current.
Work, Power & Efficiency
Definition of power as rate of energy transfer; specific calculation of power in electrical systems; concept of dissipation of energy into non-useful forms by devices; concept of efficiency; calculation of efficiency.