Key term
CCEA A-Level Physics 1210
Physical Quantities, Scalars and Vectors
Moments and Equilibrium
Linear Motion and Dynamics
Newton's Laws of Motion
Linear Momentum and Impulse
Work, Energy and Power
Current, Charge and Potential Difference
Resistance and Resistivity
Topic overviewResistance and Ohm's lawOhmic and non-ohmic behaviourResistors in series and in parallelInvestigating current, voltage and resistance in series and parallel circuitsElectrical power and energy in resistive circuitsResistivity and the equation R = ρl/AMeasuring the resistivity of a metalCurrent–voltage characteristics of a conductor, a lamp and a diodeResistance, temperature and superconductivity
Internal Resistance and Potential Dividers
Topic overviewInternal resistance and terminal potential differenceConsequences of internal resistance for external circuitsMeasuring electromotive force and internal resistanceThe potential divider and variable outputPotential dividers in lighting and heating control circuitsLoaded potential dividers and output voltage calculations
Waves
Refraction
Lenses
Superposition, Interference and Diffraction
Topic overviewSuperposition of wavesStanding waves, nodes and antinodesStanding waves on stretched stringsStanding waves in a pipe closed at one endMeasuring the speed of sound with a resonance tubeConditions for observable interferencePath difference and phase differenceYoung's double slitDiffraction at a single slitThe diffraction grating
Quantum Physics
Wave-Particle Duality
Astronomy
Practical Skills and Data Analysis
Topic overviewChoosing and using measuring instrumentsPrecision, accuracy and recording measurementsUsing the cathode ray oscilloscope to measure voltage and frequencyTables, graphs and presenting resultsLinearising a relationship and using the gradientAbsolute and percentage uncertaintyCombining uncertainties and uncertainty on a graphRandom and systematic error, reliability and refining an experiment
Deformation of Solids
Thermal Physics
Topic overviewBoyle's law, Charles's law and the pressure lawThe ideal gas equation pV = nRTThe Avogadro constant, the mole and pV = NkTInternal energy and the distribution of molecular energyThe kinetic theory equation pV = ⅓Nm⟨c²⟩Average molecular kinetic energy and temperatureAbsolute zero and the kelvin scaleSpecific heat capacity and the electrical method
Uniform Circular Motion
Simple Harmonic Motion
Topic overviewDefining simple harmonic motion and a = −ω²xDisplacement, velocity and acceleration: x = A cos ωtThe simple pendulum and T = 2π√(l/g)The loaded spiral spring and T = 2π√(m/k)SHM graphs and finding velocity from a gradientFree vibrations, forced vibrations and resonanceDamping: light, critical and over-damping
The Nucleus and Radioactive Decay
Topic overviewAlpha-particle scattering and the nuclear atomNuclear radius and nucleon numberThe density of nuclear matterAlpha, beta and gamma radiation: nature, penetration and rangeNuclear equations and changes in nucleon and proton numberThe random and exponential nature of radioactive decayActivity, the decay constant and A = −λNExponential decay calculations with A = A₀e^(−λt)Half-life and measuring it
Nuclear Energy, Fission and Fusion
Gravitational Fields
Electric Fields
Capacitors
Magnetic Fields
Charged Particles and Accelerators
Newton's Laws of Motion
Friction as a force opposing motion
- 3 things to know
- Unit AS 1
Overview
Recall questions on what friction is and in which direction it acts, the energy transfer it causes, drag and why it grows with speed, static against sliding friction, how friction lets a car accelerate, where it is useful and where a nuisance, ways of reducing it, and calculations on braking.
What you need to know
Answer each one before you reveal it.
Your recallNot started
Numbers
A car of mass 900 kg travelling at 18 m s⁻¹ brakes and stops in 30 m. Calculate the average braking force.
Key term
Explain why a skydiver who opens a parachute slows down rather than continuing at the same speed.
Questions from this subtopic
Each one with the model answer underneath.
- 1
What is friction?
Model answer
Friction is a contact force acting along the surfaces where two bodies touch, and it always acts so as to oppose the relative motion, or the tendency to relative motion, of those surfaces.
- 2
State the direction in which friction acts on a block sliding across a rough table.
Model answer
It acts parallel to the table surface and in the direction opposite to the sliding motion of the block.
- 3
Explain why a puck sliding across a rough floor slows down and stops.
Model answer
Friction acts backwards along the floor, giving a resultant force opposite to the motion, and by Newton's second law this produces a deceleration that continues until the puck is at rest.
- 4
Describe the energy transfer that takes place when friction acts.
Model answer
Kinetic energy of the moving object is transferred to internal energy of the two surfaces and the surrounding air, so the surfaces become warmer.
- 5
What is meant by drag?
Model answer
Drag is the frictional force exerted on a body by the fluid it moves through, acting opposite to the motion and growing larger as the speed increases.
- 6
Explain why the drag force on a moving object increases with its speed.
Model answer
At a higher speed the object pushes aside more fluid each second and pushes it aside faster, so a larger force is needed to move the fluid and, by Newton's third law, the fluid pushes back on the object more strongly.
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 Newton's Laws of 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.
Or £46 a year, about £3.83 a month. Cancel anytime.