Numbers
Edexcel A-Level Physics 9PH0
Working as a Physicist
Topic overviewSI base units, derived units and homogeneityUnit prefixes, conversion and order-of-magnitude estimatesResolution, random errors and systematic errorsUncertainty and how uncertainties combineImproving measurements, graphs and evaluating resultsPeer review, publication and scientific integrityRisk, benefit and the role of science in society
Mechanics
Topic overviewThe equations of uniformly accelerated motionDisplacement-time and velocity-time graphsScalars and vectorsResolving vectors and finding resultantsProjectile motionFree-body diagrams and Newton's first and second lawsNewton's third law, mass and weightTerminal velocity and measuring g by free fallLinear momentum and its conservationElastic and inelastic collisions in one dimensionThe moment of a forceCentre of gravity, equilibrium and the principle of momentsWork done by a forceKinetic and gravitational potential energyConservation of energy and dissipationPower, and the equation P = FvEfficiency and wasted energy
Electric Circuits
Topic overviewCurrent, charge and potential differenceResistance, Ohm's law and ohmic behaviourElectrical power and energyKirchhoff's laws: the current and potential difference rulesCombining resistances in series and parallelCircuit calculations, meters and component failureI-V characteristics of conductors, lamps and diodesThermistors, light dependent resistors and resistance changeResistivity and determining it experimentallyCharge carriers, drift velocity and I = nqvAThe potential divider equation and the loading effectSensing circuits with thermistors and light dependent resistorsElectromotive force, internal resistance and lost voltsMeasuring e.m.f. and internal resistance, and cells in combination
Materials
Topic overviewDensity and how it is measuredUpthrust and Archimedes' principleFloating, sinking and upthrust calculationsViscosity, laminar flow and Stokes' lawTerminal velocity of a sphere falling through a liquidMeasuring viscosity by the falling-ball methodHooke's law, stress and strainThe Young modulus and calculations with itDetermining the Young modulus of a wireForce-extension graphs, elastic and plastic deformationStress-strain graphs, ductile and brittle materialsElastic strain energy
Waves and Particle Nature of Light
Topic overviewDescribing a progressive waveThe wave equation and its useLongitudinal and transverse wavesDisplacement-distance and displacement-time graphsMeasuring the speed of sound with an oscilloscopeWavefronts, superposition and phaseCoherence, path difference and phase differenceInterference in practiceStationary waves, nodes and antinodesHarmonics on a stretched stringInvestigating a vibrating string, and air columnsIntensity, the inverse square law and refractive indexRefraction, wave speed and the critical angleTotal internal reflection and measuring refractive indexLenses, ray diagrams and the images they formLens power and the thin lens equationLens calculations and magnificationReflection, transmission and the pulse-echo principlePulse-echo calculations, resolution and ultrasoundPolarisation and diffractionSingle-slit patterns and the diffraction grating equationGrating spectra and measuring wavelengthElectron diffraction and the de Broglie equationde Broglie calculations and wave-particle dualityPhotons and photon energyModels of light and the electronvoltLine spectra and atomic energy levelsThe photoelectric effect and Einstein's equationEvidence for the photon model and photoelectric calculations
Further Mechanics
Topic overviewImpulse and force-time graphsConservation of momentum in two dimensionsInvestigating momentum and analysing collisions on videoElastic and inelastic collisionsKinetic energy, momentum and collision calculationsThe radian, angular displacement and angular velocityAngular velocity, period and frequency of rotationCentripetal accelerationCentripetal force and what provides itVertical loops and centripetal force calculations
Electric and Magnetic Fields
Topic overviewElectric fields and electric field strengthField strength calculations and field diagramsCoulomb's law and the field of a point chargeInverse-square behaviour and combining fieldsElectric potential and field strength as a potential gradientUniform fields between parallel plates, and the potential near a point chargeEquipotentials, field diagrams and work doneCapacitance and the energy stored in a capacitorCapacitor charge and energy calculationsCharging and discharging graphs and the time constantThe exponential decay equations and logarithmic graphsInvestigating capacitor discharge and time-constant calculationsMagnetic flux density, flux and flux linkageForces on currents and moving chargesThe conditions for inducing an e.m.f.Faraday's law and Lenz's lawFlux linkage graphs and induced e.m.f. calculationsAlternating current, peak and r.m.s. valuesOscilloscope traces and alternating current calculations
Nuclear and Particle Physics
Topic overviewNuclide notation, isotopes and the alpha scattering experimentConclusions from alpha scattering and the changing model of the atomThermionic emission and linear acceleratorsThe cyclotron and the radius of a charged particle's pathParticle tracks, conservation laws and why high energies are neededMass-energy equivalence, pair production and annihilationParticle energy units and relativistic lifetimesBaryons, mesons, leptons and quark compositionThe six quarks, antiparticles and fundamental particlesConservation of charge, baryon number and lepton numberQuark changes in beta decay and testing particle equations
Thermodynamics
Topic overviewSpecific heat capacity and specific latent heatMeasuring specific heat capacity and calibrating a thermistorMeasuring specific latent heatInternal energy, temperature and absolute zeroMean kinetic energy and the absolute temperature scaleThe kinetic theory equation and its derivationThe ideal gas equation and molecular kinetic energyBoyle's law and investigating a fixed mass of gasBlack body radiation and Wien's lawThe Stefan-Boltzmann law and stellar calculations
Space
Nuclear Radiation
Topic overviewMass deficit, binding energy and the atomic mass unitBinding energy per nucleon, fission and fusionBackground radiation and the three types of nuclear radiationIonising power, penetration and changes in the nucleusNuclear equations and investigating gamma absorptionActivity, the decay constant and half-lifeDecay graphs and half-life calculations
Gravitational Fields
Oscillations
Topic overviewThe conditions for simple harmonic motionDisplacement, velocity and acceleration in simple harmonic motionThe mass-spring oscillator and the simple pendulumDisplacement, velocity and acceleration graphsReading period, amplitude and speed from oscillation graphsEnergy in an undamped oscillationDamping and where the energy goesFree and forced oscillations and resonanceResonance in practice and determining an unknown mass
Oscillations
- 9 subtopics
- 15 things to know
- Papers 2 and 3
What Oscillations covers
Paper 2 content on simple harmonic motion: the condition that defines it, the displacement, velocity and acceleration equations and graphs, the mass-spring oscillator and the simple pendulum, energy in an oscillation, damping, and resonance.
Where it is assessed
Papers 2 and 3
Advanced Physics II, then the general and practical principles paper.
Check the Pearson Edexcel specification ↗The 9 subtopics
Each one has its own page.
- The conditions for simple harmonic motionRecall questions on the definition, the condition on the restoring force, what the minus sign means, the acceleration-displacement relationship, and an oscillation that is not simple harmonic.Open →
- Displacement, velocity and acceleration in simple harmonic motionRecall questions on amplitude, period, frequency and angular frequency, the velocity and acceleration equations, and the phase relationships between the three quantities.Open →
- The mass-spring oscillator and the simple pendulumRecall questions on both period equations and the assumption behind the pendulum's, why amplitude and bob mass do not matter, and determining g or a spring constant from oscillations.Open →
- Displacement, velocity and acceleration graphsRecall questions on the shapes of the three graphs, what each gradient gives, where velocity and acceleration are zero, and the phase difference between them.Open →
- Reading period, amplitude and speed from oscillation graphsRecall questions on obtaining period and amplitude accurately, estimating maximum speed from a gradient, what the area under a velocity-time graph gives, and how damping changes the trace.Open →
- Energy in an undamped oscillationRecall questions on the energy changes through a cycle, where kinetic and potential energy peak, the form the potential energy takes, and how total energy depends on amplitude.Open →
- Damping and where the energy goesRecall questions on what damping is, where the energy goes, light, critical and heavy damping, whether energy is conserved, and why plastic deformation damps so effectively.Open →
- Free and forced oscillations and resonanceRecall questions on free and forced oscillations, natural frequency, what resonance is, why energy transfer peaks there, and how damping changes the resonance curve.Open →
- Resonance in practice and determining an unknown massRecall questions on where resonance is useful and where it is a problem, reducing it in a structure, and the calibration graph that turns a resonant frequency into a mass.Open →
What you need to know
Answer each one before you reveal it.
Your recallNot started
Numbers
What do the period and the frequency of an oscillation mean, and what is angular frequency and its unit?
Numbers
What is the equation for the velocity of an oscillator released from maximum displacement, and where in the cycle is it moving fastest?
Numbers
What is the equation for the acceleration of an oscillator, where is it greatest, and what is its phase relationship with displacement?
Numbers
What is the phase relationship between displacement and velocity, what is the period of a mass-spring oscillator, and what happens if the mass is quadrupled?
Numbers
What does a displacement-time graph look like for an oscillator released from maximum displacement, what does its gradient give, and where is that gradient zero?
Numbers
What does a velocity-time graph look like for an oscillator, what does its gradient give, and where is the acceleration zero?
Numbers
How do the graphs change when an oscillator's amplitude is doubled, and how does light damping change the displacement-time graph?
Key term
What energy changes take place during one cycle of an undamped oscillation, and where in the cycle are the kinetic and potential energies greatest?
Process
What form does the potential energy take for a pendulum and for a horizontal mass-spring, and how does total energy depend on amplitude?
Process
What happens to total energy if the amplitude halves, what does a total energy against displacement graph look like, and how does the amplitude of a lightly damped oscillator change with time?
Key term
Is energy conserved in a damped oscillation?
Numbers
Which straight-line graph relates the resonant frequency of a mass-spring system to its mass, and how is an unknown mass read off it?
Key term
What is the natural frequency of a system, and what is the key difference between a free and a forced oscillation?
Evaluation
How do a stiffer spring and added mass change the resonant frequency, what is the main uncertainty in finding it, and why is the driving amplitude kept constant?
Take Oscillations further
The same content, four other ways.
Commonly confused
Pairs that lose marks when they are blurred together.
Free oscillation vs Forced oscillation
Free oscillation: motion at a system’s natural frequency. Forced oscillation: motion driven by an external periodic force.
Damping vs Resonance
Damping: process removing energy from an oscillator. Resonance: large response when driving and natural frequencies match.
Amplitude vs Displacement
Amplitude: maximum distance from equilibrium. Displacement: instantaneous directed distance from equilibrium.
Questions from this topic
Each one with the model answer underneath.
- 1
What is meant by simple harmonic motion?
Model answer
It is motion in which the acceleration is proportional to the displacement from the equilibrium position and is always directed back towards that position.
- 2
State the condition on the restoring force for simple harmonic motion:
Model answer
The restoring force must obey F = −kx, so it is proportional to displacement and acts in the opposite direction.
- 3
What is the significance of the minus sign in F = −kx?
Model answer
It shows the force always acts back towards the equilibrium position, opposite to the displacement.
- 4
Why does a mass hanging on a spring perform simple harmonic motion when it is displaced vertically?
Model answer
An extra displacement x stretches the spring further, producing an extra force kx directed back towards equilibrium, which is exactly the condition F = −kx.
- 5
What is an example of an oscillation that is not simple harmonic, and why is it not?
Model answer
A ball bouncing on the ground is not simple harmonic, because the force on it is not proportional to its displacement from any equilibrium position.
- 6
State the relationship between acceleration and displacement for a simple harmonic oscillator:
Model answer
a = −ω²x, where ω is the angular frequency.
What is inside Levo
Six ways to work the same material.
Oscillations revision questions
- What does Oscillations cover in Edexcel A-Level Physics?
- 9 subtopics: the conditions for simple harmonic motion, displacement, velocity and acceleration in simple harmonic motion, the mass-spring oscillator and the simple pendulum, displacement, velocity and acceleration graphs, reading period, amplitude and speed from oscillation graphs, energy in an undamped oscillation, damping and where the energy goes, free and forced oscillations and resonance and resonance in practice and determining an unknown mass. Each one has its own page with questions and model answers.
- How is Oscillations organised?
- By the Edexcel 9PH0 specification, subtopic by subtopic, so it matches the order you are taught it in.
Every question in Oscillations, on a schedule.
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