Key term
OCR A-Level Physics B H557
Planning
Implementing
Analysis
Evaluation
Practical Skills
Use of Apparatus and Techniques
Fundamental Data Analysis
Imaging and Signalling
Topic overviewReal images and the curvature of wave-frontsLens power and focal lengthThe thin lens equation and the Cartesian conventionLinear magnificationMeasuring the power and focal length of a converging lensImages as arrays of numbersBits, bytes and the information in an imageEnhancing a digital imageWave-forms, frequency and wave speedSampling and digitising an analogue signalNoise, resolution and digital transmissionPolarisation of electromagnetic waves
Sensing
Topic overviewCurrent and the flow of chargePotential difference, e.m.f. and energy transferResistance, conductance and Ohm's lawSeries and parallel combinationsPower and energy in electric circuitsInternal resistance and e.m.f.Kirchhoff's laws and conservation in circuitsResistivity and conductivityCharge carrier number density in metals, semiconductors and insulatorsCurrent-potential difference characteristics and circuit componentsThe potential dividerSensing circuits and calibration
Mechanical Properties of Materials
Topic overviewElastic and plastic deformation and fractureHooke's law and force-extension graphsElastic strain energyStress, strain and the Young modulusMeasuring the Young modulus and fracture stress of a metalDescribing and comparing materialsMetals, ceramics and polymersDirect evidence for the size and spacing of particles
Waves and Quantum Behaviour
Topic overviewWaves, phase and superpositionStanding waves on stringsStanding waves in air columns and the speed of soundRefraction, refractive index and Snell's lawTwo-slit interferenceDiffraction at a narrow apertureThe diffraction gratingMeasuring the wavelength of lightPhotons and the quantum E = hfEvidence that photons exchange energy in quantaQuantum behaviour: phasors and probability of arrivalElectron diffraction and the de Broglie wavelength
Space, Time and Motion
Topic overviewScalars, vectors and their representationResolving and adding vectorsDescribing motion: displacement, velocity and accelerationMotion graphsThe kinematic equations for constant accelerationProjectiles and motion in two dimensionsMeasuring motion in the laboratoryDetermining the acceleration of free fallNewton's laws of motionTerminal velocity and resistive forcesMomentum and impulseConservation of momentum and collisionsWork, energy and its conservationPower and modelling motion in small time steps
Creating Models
Topic overviewCapacitance and charge storageEnergy stored on a capacitorCapacitor discharge and the exponential modelThe time constant of an RC circuitCharging a capacitorInvestigating capacitor charge and dischargeRadioactive decay as a random processActivity, decay constant and half-lifeDetermining the half-life of an isotopeIterative numerical models of exponential changeExponential curves on linear and logarithmic scalesSimple harmonic motion: the defining relationshipSolutions and graphs of simple harmonic motionModelling oscillations step by stepEnergy in simple harmonic motionPeriod of a mass–spring system and a simple pendulumFree and forced vibrations, damping and resonance
Out Into Space
Topic overviewGravitational and kinetic energy changesMotion in a uniform gravitational fieldGravitational force and the radial fieldGravitational field strengthGravitational potential energy in a radial fieldGravitational potential and equipotentialsGraphs and diagrams of gravitational fieldsAngular velocity and motion in a horizontal circleCircular gravitational orbits
Our Place in the Universe
Matter: Very Simple
Topic overviewEnergy transfer and specific thermal capacityFinding specific thermal capacity by an electrical methodIdeal gases and the gas lawsInvestigating the gas laws and absolute zeroMoles, the Avogadro constant and the Boltzmann constantThe equation of state for an ideal gasImpulse and force–time graphsThe kinetic theory of ideal gasesTemperature, average energy per particle and internal energyRandom walk of molecules in a gas
Matter: Hot or Cold
Electromagnetism
Topic overviewMagnetic flux, B-fields and flux linkageElectromagnetic induction: Faraday's and Lenz's lawsGraphs of current, flux and induced e.m.f.The dynamoThe transformerEddy currents and real transformersForces on current-carrying conductorsMagnetic circuits, permeance and machine designInvestigating induction, flux density and transformers
Charge and Field
Topic overviewThe uniform electric fieldRadial fields and the inverse square lawElectric potential and potential energyField and potential graphsField lines and equipotential surfacesThe electronvolt and accelerating chargesMillikan's experiment and the discreteness of chargeMoving charges in magnetic fieldsComparing electric and gravitational fields
Probing Deep Into Matter
Topic overviewParticle accelerators and high-energy beamsScattering and the nuclear atomPaths of scattered particles and closest approachDiscrete energy levels in atomsElectron standing waves and the confined electronQuarks, hadrons and leptonsConservation laws and nuclear equationsCharged particles in detectors and magnetic fieldsRelativistic energy and the relativistic factor
Ionising Radiation and Risk
Topic overviewThe nature of ionising radiationsEffects on living tissue and radiation safetyAbsorbed dose, effective dose and riskBinding energy and nuclear stabilityThe Nuclear Valley and modes of decayFission, fusion and nuclear powerActivity, half-life and the decay constantInvestigating absorption and half-life
Out Into Space
- 9 subtopics
- 27 things to know
- Components 01, 02 and 03
What Out Into Space covers
Out Into Space is examined in all three written papers — the specification states that Components 01, 02 and 03 each assess content from across all the teaching modules, so nothing is confined to one paper. It covers gravitational and kinetic energy changes, motion in a uniform gravitational field, gravitational force and the radial field, gravitational field strength, gravitational potential energy in a radial field, gravitational potential and equipotentials, graphs and diagrams of gravitational fields, angular velocity and motion in a horizontal circle and circular gravitational orbits.
Where it is assessed
Components 01, 02 and 03
Every module can be assessed on any of the three papers.
Check the OCR specification ↗The 9 subtopics
Each one has its own page.
- Gravitational and kinetic energy changesRecall questions on the near-surface potential energy equation, work done by a force, why mass cancels in a landing speed, path independence, and areas under force–distance graphs.Open →
- Motion in a uniform gravitational fieldRecall questions on field lines and equipotentials, showing newtons per kilogram equals metres per second squared, treating projectile motion as two independent directions, and where this approximation fails.Open →
- Gravitational force and the radial fieldRecall questions on F = −GMm/r² and its minus sign, the gravitational constant G, the inverse square law, treating planets as point masses, satellite and sphere force calculations, doubling separation, why everyday attraction is unnoticeable, Newton's third law pairs, radial field lines, a larger planet's surface force, and gravity against the strong nuclear force.Open →
- Gravitational field strengthRecall questions on the defining equation and unit, inverse-square variation around a planet, adding fields from two bodies and where they cancel, apparent weightlessness in orbit, and field-line spacing.Open →
- Gravitational potential energy in a radial fieldRecall questions on E = −GMm/r and why it is negative, the zero at infinite separation, how potential energy changes with distance, satellite and spacecraft calculations, constant energy in a circular orbit, when mgh is enough, escape velocity v = √(2GM/r) and why it does not depend on mass, negative total energy in a bound orbit, and the energy–distance graph.Open →
- Gravitational potential and equipotentialsRecall questions on gravitational potential V = −GM/r and its unit, its link to potential energy, potential as a scalar, the potential at the Earth's surface, equipotential surfaces around a planet and why moving along one needs no work, their relation to field lines, escape energy per kilogram, the energy to move a probe, equipotential spacing, and which way a released mass moves.Open →
- Graphs and diagrams of gravitational fieldsRecall questions on the areas under field– and force–distance graphs, finding force or field from a gradient, estimating an area under a curve, equipotential diagrams, and why potential stays below zero.Open →
- Angular velocity and motion in a horizontal circleRecall questions on angular velocity and its unit, radians in a revolution, ω = 2π/T and v = ωr, centripetal acceleration a = v²/r and its direction, F = mv²/r and F = mrω², why uniform circular motion is accelerated, calculations for a stone, a car and a whirled mass, why centripetal force does no work, and what holds a satellite in orbit.Open →
- Circular gravitational orbitsRecall questions on gravity supplying the centripetal force, deriving orbital speed and the period–radius relation, why satellite mass drops out, geostationary and polar orbits, and decaying low orbits.Open →
What you need to know
Answer each one before you reveal it.
Your recallNot started
Key term
Why is gravitational potential energy defined as negative?
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Why can mgh be used near the surface while −GMm/r is needed for a rocket leaving the Earth?
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What equation gives the change in gravitational potential energy near the Earth's surface?
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What equation gives the gravitational force between two point masses?
Evaluation
What is the field strength at a distance r from a point mass M?
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How is gravitational potential related to gravitational potential energy?
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How is the gravitational force found from a graph of gravitational potential energy against distance?
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How is angular velocity related to the period of the motion?
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Why does orbital speed not depend on the mass of the satellite?
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A 70 kg climber ascends 12 m. What is the gain in gravitational potential energy?
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Why do all objects in free fall near the Earth have the same acceleration?
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Why does the radial component of the gravitational force carry a minus sign?
Numbers
Calculate the gravitational field strength at the surface of an Earth of mass 5.97 × 10²⁴ kg and radius 6.37 × 10⁶ m.
Key term
What is the gravitational potential at a distance r from a point mass M?
Evaluation
How is field strength found from a graph of gravitational potential against distance?
Key term
How is linear speed related to angular velocity in circular motion?
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State the relationship between the period and the radius of a circular orbit in words.
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What relationship links work done, force and displacement?
Evaluation
A ball thrown horizontally at 15 m s⁻¹ falls for 2.0 s. How far horizontally does it travel?
Key term
State the value and unit of the universal gravitational constant.
Evaluation
What is the field strength 6.37 × 10⁶ m above the surface of the Earth?
Key term
What is the gravitational potential energy of a mass m at a distance r from a mass M?
Numbers
Calculate the gravitational potential at the surface of an Earth with GM = 3.98 × 10¹⁴ N m² kg⁻¹ and radius 6.37 × 10⁶ m.
Key term
Why must a change of potential be found as an area rather than by a single multiplication?
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What is the expression for centripetal acceleration in terms of speed and radius?
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A satellite of orbital radius 6.77 × 10⁶ m travels at 7.7 × 10³ m s⁻¹. What is its period?
Take Out Into Space further
The same content, four other ways.
Commonly confused
Pairs that lose marks when they are blurred together.
Gravitational field strength g vs Gravitational potential V
Gravitational field strength g: the gravitational pull per kilogram on a small test mass at that point, in N kg⁻¹, and a vector directed towards the mass producing it. Gravitational potential V: The work done per kilogram in bringing a small test mass from infinity to that point, in J kg⁻¹, and a scalar that is negative everywhere.
mgh vs −GMm/r
mgh: the change in energy when a mass is raised through a small height near the surface, where the pull per kilogram is effectively constant. −GMm/r: The absolute energy in joules that one particular mass has in a radial field, negative everywhere and rising towards zero at infinity.
Inverse square for force vs Inverse for potential
Inverse square for force: the pull between two masses falls as 1/r², so tripling the separation cuts it to a ninth. Inverse for potential: The energy per kilogram at a point falls as −1/r, so doubling the distance halves it rather than quartering it.
Questions from this topic
Each one with the model answer underneath.
- 1
What equation gives the change in gravitational potential energy near the Earth's surface?
Model answer
The change is ΔE = mgΔh, where g is the gravitational field strength.
- 2
Why is mgh valid only close to the Earth's surface?
Model answer
It assumes the field strength g is constant, which is true only over heights small compared with the radius of the Earth.
- 3
A 70 kg climber ascends 12 m. What is the gain in gravitational potential energy?
Model answer
ΔE = mgh = 70 × 9.81 × 12 = 8.2 × 10³ J.
- 4
What relationship links work done, force and displacement?
Model answer
The work done is ΔE = FΔs, where the displacement is measured along the direction of the force.
- 5
Why is no work done when a force acts at right angles to the motion?
Model answer
There is no displacement in the direction of the force, so the product FΔs along that direction is zero.
- 6
A ball of mass 0.20 kg is dropped from 1.8 m. What is its speed on landing, ignoring air resistance?
Model answer
From mgh = ½mv², v = √(2 × 9.81 × 1.8) = 5.9 m s⁻¹.
What is inside Levo
Six ways to work the same material.
Out Into Space revision questions
- What does Out Into Space cover in OCR A-Level Physics B?
- 9 subtopics: gravitational and kinetic energy changes, motion in a uniform gravitational field, gravitational force and the radial field, gravitational field strength, gravitational potential energy in a radial field, gravitational potential and equipotentials, graphs and diagrams of gravitational fields, angular velocity and motion in a horizontal circle and circular gravitational orbits. Each one has its own page with questions and model answers.
- How is Out Into Space organised?
- By the OCR H557 specification, subtopic by subtopic, so it matches the order you are taught it in.
Every question in Out Into Space, 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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