Numbers
OCR A-Level Physics A H556
Practical Skills in the Written Papers
The Practical Endorsement
Topic overviewAnalogue and digital measuring instrumentsImproving accuracy with repeat timing, fiducial markers and plumb linesTiming, calipers and micrometersConstructing and testing circuitsSignal generators and oscilloscopesGenerating and measuring wavesData loggers, modelling software and ionising radiation
Physical Quantities and Units
Making Measurements and Analysing Data
Nature of Quantities
Motion
Forces in Action
Work, Energy and Power
Materials
Newton’s Laws of Motion and Momentum
Charge and Current
Energy, Power and Resistance
Electrical Circuits
Waves
Topic overviewProgressive waves and their propertiesThe wave equationReflection, refraction and diffractionWave graphs and intensityThe electromagnetic spectrumPolarisationRefraction and refractive indexCritical angle and total internal reflectionThe principle of superpositionInterference, coherence and path differenceTwo-source interference, Young's double-slit experiment and the diffraction gratingForming stationary wavesStationary waves on strings and in air columnsMeasuring the speed of soundNode spacing, amplitude and phase in stationary wavesHarmonics and the fundamental mode
Quantum Physics
Thermal Physics
Topic overviewThermal equilibrium and absolute temperatureThe kinetic model of solids, liquids and gasesBrownian motion and internal energySpecific heat capacityMeasuring specific heat capacitySpecific latent heatMeasuring specific latent heatMoles, the Avogadro constant and kinetic theoryGas laws, the ideal gas equation and r.m.s. speedMaxwell-Boltzmann distribution, Boltzmann constant and internal energy
Oscillations
Gravitational Fields
Astrophysics and Cosmology
Topic overviewThe solar system and the birth of a starThe death of a low-mass starSupernovae, neutron stars and black holesThe Hertzsprung-Russell diagramEnergy levels and emission spectraAbsorption spectra and spectral linesPhoton energy and the diffraction gratingWien's law and Stefan's lawAstronomical distances, parallax and the cosmological principleDoppler shift and Hubble's lawThe expanding universe and the Big BangEvidence for the Big Bang and dark energy
Capacitors
Topic overviewCapacitance and charging a capacitorCapacitors in seriesCapacitors in parallel and combined circuitsEnergy stored by a capacitorCharging and discharging through a resistorInvestigating capacitor dischargeThe time constantIterative modelling, exponential decay and the constant-ratio property
Electric Fields
Electromagnetism
Nuclear and Particle Physics
Topic overviewAlpha-particle scattering and the nuclear modelProton number, nucleon number and isotopesThe strong nuclear force and nuclear radiusParticles, antiparticles and hadronsLeptons and the quark modelQuark composition and chargesBeta decay in the quark modelRadioactive decay and the three radiationsNuclear decay equationsActivity, decay constant and half-lifeExponential decay and radioactive datingMass-energy equivalenceAnnihilation, mass defect and binding energyBinding energy per nucleon and induced fissionThe fission reactor and nuclear wasteNuclear fusion and balancing nuclear equations
Work, Energy and Power
- 3 subtopics
- 9 things to know
- Papers 1 and 3
What Work, Energy and Power covers
Work as energy transferred, the interchange of kinetic and potential energy, and the rate at which energy is transferred.
Where it is assessed
Papers 1 and 3
Forces and motion, examined on Modelling Physics and Unified Physics.
Check the OCR specification ↗The 3 subtopics
Each one has its own page.
- Work done and conservation of energyRecall questions on work done and its unit, W = Fx cos θ and calculations with it, the principle of conservation of energy, forms of energy and how energy transfer relates to work done.Open →
- Kinetic and gravitational potential energyRecall questions on kinetic energy and gravitational potential energy, their equations, calculations and derivations from first principles, and the exchange between them for a freely falling object.Open →
- Power and efficiencyRecall questions on power and the watt, P = W/t and P = Fv with their derivation and calculations, efficiency in terms of energy and power, and why efficiency is always below 100%.Open →
What you need to know
Answer each one before you reveal it.
Your recallNot started
Numbers
What is kinetic energy, how is it calculated, and how is the transfer of energy related to work done?
Numbers
When an object is lifted through a height h at constant velocity, what force is needed, how is the work done calculated, and what happens to that work?
Numbers
In deriving the kinetic energy equation from first principles, what two equations do you start with?
Numbers
What is the SI unit of power, and how is it defined?
Numbers
In deriving P = Fv, what equation do you start with?
Key term
What is the definition of work done in physics?
Key term
What is kinetic energy?
Key term
State the equation for power delivered by a force moving an object at constant velocity.
Take Work, Energy and Power further
The same content, four other ways.
Commonly confused
Pairs that lose marks when they are blurred together.
Work done vs Power
Work done: the energy transferred when a force moves its point of application. Power: the rate at which that energy is transferred.
Kinetic energy vs Gravitational potential energy
Kinetic energy: the energy a body has because it is moving. Gravitational potential energy: the energy a body has because of its position in a gravitational field.
Conservation of energy vs Efficiency
Conservation of energy: the principle that the total energy of a closed system never changes. Efficiency: the fraction of the energy supplied that emerges as useful output.
Questions from this topic
Each one with the model answer underneath.
- 1
What is the definition of work done in physics?
Model answer
Work done is the energy transferred when a force moves an object through a distance in the direction of the force.
- 2
What is the SI unit of work done, and how is it defined in base units?
Model answer
The SI unit of work done is the joule (J), where 1 joule equals 1 newton metre, which is 1 kg m² s⁻² in base units.
- 3
State the equation used to calculate work done when a force acts at an angle to the displacement.
Model answer
W = Fx cos θ, where F is the force, x is the displacement, and θ is the angle between the force and displacement vectors.
- 4
In the equation W = Fx cos θ, what does the angle θ represent?
Model answer
θ is the angle between the force vector and the displacement vector.
- 5
Why is the cosine function used when calculating work done by a force at an angle?
Model answer
The cosine function gives the component of the force acting in the direction of the displacement, since only this component does work.
- 6
Calculate the work done when force = 54 N, displacement = 88.9 m, angle = 38°.
Model answer
Work done = 54 × 88.9 × cos 38° = 3780 J.
What is inside Levo
Six ways to work the same material.
Work, Energy and Power revision questions
- What does Work, Energy and Power cover in OCR A-Level Physics A?
- 3 subtopics: work done and conservation of energy, kinetic and gravitational potential energy and power and efficiency. Each one has its own page with questions and model answers.
- How is Work, Energy and Power organised?
- By the OCR H556 specification, subtopic by subtopic, so it matches the order you are taught it in.
Every question in Work, Energy and Power, 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.
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