Key term
Edexcel GCSE Physics 1PH0
Key Concepts of Physics
Motion and Forces
Topic overviewScalar and vector quantitiesExamples of vectors and scalars, and velocitySpeed, distance, time and distance-time graphsAcceleration and the equation v squared minus u squaredVelocity-time graphs and free fallMeasuring speed in the laboratory, and typical everyday speedsNewton's first law, and investigating force, mass and accelerationNewton's second and third lawsWeight, mass and gravitational field strengthReaction time, stopping distance and large decelerationsFactors affecting stopping distance and reaction timeBraking distance, speed and work done
Conservation of Energy
Waves
Topic overviewWhat waves transfer, and the evidence for itFrequency, wavelength, amplitude and periodLongitudinal and transverse wavesThe wave equationMeasuring wave speed, and what happens at a boundaryMeasuring waves in ripple tanks, strings and solidsReflection, refraction, transmission and absorption at a boundary
Light and the Electromagnetic Spectrum
Topic overviewReflection, refraction and total internal reflectionWhy objects appear colouredLenses, ray diagrams and imagesProperties of electromagnetic wavesInvestigating refraction in glass blocksThe groups of the electromagnetic spectrumThe continuous spectrum, and what our eyes can detectEmitting and absorbing thermal radiationHow radiation is generated, and why danger rises with frequencyHarmful effects of excessive exposure to radiationUses of electromagnetic radiation
Radioactivity
Topic overviewThe atom and the size of atomsIsotopes, atomic number and mass numberRelative masses and charges of subatomic particlesElectron orbits and energy levelsForming ions, and how the atomic model changedTypes of ionising radiationBackground radiation and detecting radioactivityAlpha, beta and gamma, and their penetrating powerBeta-minus and beta-plus decayEffects of decay on atomic number and mass numberBalancing nuclear equationsActivity and the becquerelHalf-life and the randomness of decayHalf-life calculationsUses of radioactivity, and how danger depends on half-lifeThe dangers of ionising radiationSafety precautions, contamination and irradiationRadiotherapy, medical tracers and PET scannersNuclear power and where nuclear energy comes fromFission of uranium-235 and the chain reactionControlling a reactor and generating electricityNuclear fusion and how it differs from fissionWhy fusion needs extreme conditions
Astronomy
Topic overviewWeight and gravitational field strength on other bodiesThe Solar System and the order of the planetsHow ideas about the Solar System and ways of observing it have changedOrbits of moons, planets, comets and satellitesGravity, orbital speed and stable orbitsThe Steady State and Big Bang theoriesEvidence for an expanding UniverseThe Doppler effect and red-shift in galaxiesThe life cycle of a star like the SunThe life cycle of stars more massive than the Sun
Energy – Forces Doing Work
Topic overviewEnergy stores and energy transfer diagramsChanging a system's energy, and measuring work doneWork done and the energy changes it causesGravitational potential and kinetic energy calculationsDissipation and wasted energyPower as the rate of energy transferThe watt, and calculating efficiency
Forces and Their Effects
Electricity and Circuits
Topic overviewThe atom, and drawing circuit diagramsSeries and parallel circuitsPotential difference and the voltmeterEnergy transferred by moving chargeCurrent, charge and measuring currentResistance and the equation V = IRResistors in series and in parallelDesigning circuits to test componentsInvestigating resistance in circuitsCurrent-potential difference graphs for componentsLight-dependent resistors and thermistorsThe heating effect of an electric currentUses of the heating effect, and the equation E = IVtPower as energy transferred per secondCalculating electrical powerEnergy transfer in domestic devices, and power ratingsDirect and alternating currentAlternating current and the UK mains supplyLive and neutral wires, earthing and fusesFuses in the live wire, mains voltages and electrical dangers
Static Electricity
Magnetism and the Motor Effect
Electromagnetic Induction
Particle Model
Topic overviewKinetic theory and differences in densityCalculating density, and investigating itChanges of state and internal energySpecific heat capacitySpecific latent heat and thermal insulationInvestigating the specific heat capacity of waterGas pressure and the motion of particlesAbsolute zero and the kelvin scaleCompressing gases, and the force a gas exertsPressure and volume of a fixed mass of gas
Conservation of Energy
Energy transfer diagrams and conservation of energy
- 3 things to know
- Paper 1
Overview
What energy transfer and Sankey diagrams show, arrow widths and why outputs equal the input, diagrams for a torch and a hairdryer, the principle of conservation of energy, and why energy is wasted but never used up.
What you need to know
Answer each one before you reveal it.
Your recallNot started
Key term
In a Sankey diagram, what does the width of each arrow represent?
Key term
In a Sankey diagram for an electric lamp, why is the input arrow wider than the arrow representing the light output?
Questions from this subtopic
Each one with the model answer underneath.
- 1
What does an energy transfer diagram show about a change taking place in a system?
Model answer
It shows which stores the energy starts in, which stores it ends in, and how much is transferred along each pathway.
- 2
In a Sankey diagram, what does the width of each arrow represent?
Model answer
The width of each arrow is proportional to the amount of energy transferred along that pathway.
- 3
In a Sankey diagram for an electric lamp, why is the input arrow wider than the arrow representing the light output?
Model answer
The input includes both the useful light and the energy dissipated by heating, so it is wider than the light arrow alone.
- 4
State what the total width of all the output arrows of a Sankey diagram must equal.
Model answer
It must equal the width of the input arrow, because energy is conserved.
- 5
Describe in words the energy transfer diagram for a battery-powered torch.
Model answer
Energy is transferred from the chemical store of the battery to light, and to the thermal store of the surroundings.
- 6
An energy transfer diagram for a hairdryer shows 1000 J supplied, 900 J transferred by heating and 40 J as sound. Calculate the energy transferred along the remaining pathway.
Model answer
1000 − 900 − 40 = 60 J is transferred along the remaining pathway.
Other ways to work this
The same content, four other ways.
What is inside Levo
Six ways to work the same material.
Every question in Conservation of Energy, on a schedule.
Attempt a question from memory, write the correct version, then attempt it again. Levo records the jump between your first attempt and your last, and brings each question back on the day you are due to forget it.
Or £46 a year, about £3.83 a month. Cancel anytime.