Key term
Eduqas A-Level Physics A420QS
Basic Physics
Kinematics
Dynamics
Energy Concepts
Circular Motion
Vibrations
Topic overviewDefining simple harmonic motionFrequency, period, amplitude and phaseThe displacement equation for simple harmonic motionVelocity in simple harmonic motionDisplacement and velocity graphsThe mass-spring oscillatorThe simple pendulumEnergy in simple harmonic motionFree oscillation and dampingForced oscillation and resonance
Kinetic Theory
Thermal Physics
Conduction of Electricity
Resistance
Topic overviewPotential difference and the voltResistance, Ohm's law and the ohmI–V characteristics of a metal wire and a filament lampElectrical power and energy transferThe microscopic origin of resistanceResistivity and the equation R = ρl/AResistance and temperatureSuperconductivity and the transition temperatureHigh temperature superconductors and their uses
D.C. Circuits
Capacitance
Solids Under Stress
Electrostatic and Gravitational Fields of Force
Topic overviewElectric field strength and Coulomb's lawGravitational field strength and Newton's law of gravitationField lines and equipotential surfacesElectric potential and potential energyGravitational potential and potential energyResultant fields and potentials from several sourcesComparing electric and gravitational fields
Using Radiation to Investigate Stars
Orbits and the Wider Universe
Topic overviewKepler's laws of planetary motionNewton's law of gravitation applied to planets and satellitesDeriving Kepler's third law for a circular orbitUsing orbital data to find the mass of the central objectGalactic rotation curves and dark matterThe centre of mass of a two-body systemThe Doppler shift of spectral lines and radial velocityMasses in a double system from radial velocity dataHubble's law, the age of the universe and its fate
The Nature of Waves
Wave Properties
Topic overviewDiffraction at slits and obstaclesWavelength, slit width and the spread of the beamThe principle of superpositionCoherence and the conditions for interferencePath difference and the interference conditionsYoung's double slit experimentThe historical importance of Young's experimentThe diffraction gratingComparing the grating with the double slitStationary waves
Refraction of Light
Photons
Topic overviewPhotons and the quantum of lightDemonstrating the photoelectric effectThe vacuum photocell and stopping potentialEinstein's equation and the energy graphThe electromagnetic spectrum and photon energiesLine emission and line absorption spectraAtomic energy levelsIonisation energy from an energy level diagramElectron diffraction and the de Broglie relationship
Lasers
Nuclear Decay
Topic overviewSpontaneous decay and the nature of α, β and γ radiationNuclear transformation equations and nuclide notationDistinguishing α, β and γ by ionisation, penetration and rangeBackground radiation and gamma intensity with distanceActivity, the becquerel and the decay constantThe exponential decay law and half-life
Particles and Nuclear Structure
Topic overviewThe Rutherford alpha particle scattering experimentCoulomb repulsion in the plum pudding and Rutherford modelsQuarks and leptons: the first generationAntiparticles, annihilation and their symbolsHadrons: baryons, antibaryons and mesonsQuark composition of the proton, neutron and pionsThe four fundamental interactionsConservation laws in particle reactions
Nuclear Energy
Magnetic Fields
Topic overviewThe motor effect and Fleming's left-hand ruleF = BIl sinθ and measuring magnetic flux densityThe force on a moving charge, F = Bqv sinθThe Hall effect and the Hall probeMagnetic fields due to a straight wire and a solenoidForces between current-carrying conductorsCharged particle beams and accelerators
Electromagnetic Induction
Option A: Alternating CurrentsOption A
Topic overviewElectromagnetic induction in a rotating coilFrequency, period, peak and rms valuesMean power dissipated in a resistorUsing an oscilloscope to measure voltage and frequencyInductors in a.c. circuits and inductive reactanceCapacitors in a.c. circuits and capacitive reactancePhasors, phase angle and impedanceResonance in the series RCL circuit and the Q factor
Option B: Medical PhysicsOption B
Topic overviewThe nature and properties of X-raysX-ray production and controlling the beamAttenuation of X-rays and half-value thicknessX-ray imaging, fluoroscopy and radiographyComputed tomography scanningUltrasound generation and acoustic impedanceUltrasound scanning and the Doppler techniqueMagnetic resonance and MRIRadiation effects on living matter and dosimetryRadionuclide tracers, the gamma camera and PET
Option C: The Physics of SportsOption C
Topic overviewCentre of gravity, stability and topplingMoments in muscle systems and other sporting contextsImpulse and Newton's second law in sportThe coefficient of restitutionMoment of inertiaAngular acceleration, torque and angular momentumConservation of angular momentum and rotational energyProjectiles, Bernoulli's equation and drag
Option D: Energy and the EnvironmentOption D
Mathematical Requirements (Appendix C)
Topic overviewUnits, prefixes and standard formSignificant figures and arithmetic meansUncertainty and how uncertainties combineRatios, proportionality and order of magnitude estimatesRearranging and solving physics equationsLogarithms, exponentials and decayResolving vectors, Pythagoras and trigonometryRadians, small angles, areas and volumesStraight-line graphs, gradients and interceptsTangents, areas under curves and logarithmic plots
Circular Motion
- 5 subtopics
- 15 things to know
- Component 1
What Circular Motion covers
Circular Motion is examined in Component 1, Newtonian Physics. It covers period and frequency of rotation, the radian as a measure of angle, angular velocity, centripetal acceleration and centripetal force and Applying the circular motion equations.
The 5 subtopics
Each one has its own page.
- Period and frequency of rotationPeriod of rotation of a body moving in a circle, frequency of rotation and unit of frequency and express it in SI base units.Open →
- The radian as a measure of angleRecall questions on the definition of the radian in terms of arc and radius, converting between radians and degrees, why the radian is dimensionless, the number of radians in a full turn, and where the small angle approximation applies.Open →
- Angular velocityRecall questions on the definition of angular velocity and its unit, the relations ω = 2πf and ω = 2π/T, the link v = rω and its derivation from the radian, and worked calculations for points at different radii on a rotating body.Open →
- Centripetal acceleration and centripetal forceCentripetal force on a body moving in a circle and why the passenger in a cornering car feels pushed outwards.Open →
- Applying the circular motion equationsRecall questions on what supplies the centripetal force in each case, worked force and acceleration calculations for a whirled object, a car on a bend and a satellite, the greatest speed a bend allows, and why the speed can be constant while the velocity is not.Open →
What you need to know
Answer each one before you reveal it.
Your recallNot started
Key term
State the equation linking arc length, radius and angle in radians, defining every symbol.
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State the equations linking angular velocity to period and to frequency.
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State the equation linking linear speed and angular velocity in circular motion, defining each symbol and its unit.
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State the two equations for centripetal acceleration, defining every symbol and its unit.
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State the two equations for centripetal force, defining each symbol and its unit.
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Explain why the passenger in a cornering car feels pushed outwards, when the resultant force on them acts inwards.
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Which force provides the centripetal force for a car turning a corner on a level road?
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Define the period of rotation of a body moving in a circle.
Numbers
How many radians are there in a complete circle?
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Why is a racing track banked at the corners?
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Define the frequency of rotation.
Numbers
An angle of π/4 rad is subtended at the centre of a circle of radius 1.20 m. Calculate the arc length.
Key term
State the unit of angular velocity.
Key term
Which force provides the centripetal force for a conical pendulum?
Take Circular Motion further
The same content, four other ways.
Commonly confused
Pairs that lose marks when they are blurred together.
Constant speed is possible in circular motion and vs Constant velocity is possible in circular motion and
Constant speed is possible in circular motion and: the magnitude never changes. Constant velocity is possible in circular motion and: is impossible there, because the direction is always turning.
Questions from this topic
Each one with the model answer underneath.
- 1
Define the period of rotation of a body moving in a circle.
Model answer
The period of rotation is the time taken for the body to complete one full revolution.
- 2
Define the frequency of rotation.
Model answer
The frequency of rotation is the number of complete revolutions made per unit time.
- 3
State the unit of frequency and express it in SI base units.
Model answer
Frequency is measured in hertz, and one hertz is one per second, s⁻¹.
- 4
State the relationship between period and frequency.
Model answer
The period is the reciprocal of the frequency, so T = 1/f with T in s and f in Hz.
- 5
A record turntable rotates at 45 revolutions per minute. Calculate its frequency and period of rotation.
Model answer
The frequency is 45 ÷ 60 = 0.75 Hz and the period is 1 ÷ 0.75 = 1.3 s. Multiplying 0.75 Hz by 60 s returns 45 revolutions.
- 6
A wheel makes 5.0 complete turns every second. State its frequency and calculate its period.
Model answer
The frequency is 5.0 Hz and the period is 1 ÷ 5.0 = 0.20 s. Multiplying 0.20 s by 5.0 returns 1.0 s for five turns.
What is inside Levo
Six ways to work the same material.
Circular Motion revision questions
- What does Circular Motion cover in Eduqas A-Level Physics?
- 5 subtopics: period and frequency of rotation, the radian as a measure of angle, angular velocity, centripetal acceleration and centripetal force and applying the circular motion equations. Each one has its own page with questions and model answers.
- How is Circular Motion organised?
- By the Eduqas A420QS specification, subtopic by subtopic, so it matches the order you are taught it in.
Every question in Circular Motion, 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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