Key term
AQA GCSE Combined Science Physics 8464
Atomic Structure
Topic overviewThe structure of an atomMass number, atomic number and isotopesFrom the plum pudding model to the nuclear modelChadwick, the neutron, and comparing the modelsRadioactive decay and nuclear radiationNuclear equationsHalf-lives and the random nature of radioactive decayRadioactive contamination
Electricity
Topic overviewCircuit symbols, electrical charge and currentCurrent, resistance and potential differenceOhmic conductors, filament lamps, diodes and thermistorsLight-dependent resistors, and investigating resistanceCurrent and potential difference in series and parallelConstructing circuits, and calculating in series circuitsDirect and alternating potential difference, and mains electricityPower and efficiencyAppliances, and the energy transferred by electrical workPower, and the power ratings of domestic appliancesThe National Grid
Energy
Forces
Topic overviewScalars, vectors, forces and the resultant forceGravityWork done and energy transferStretching, compressing, and the spring constantLinear and non-linear extension, and work done on a springResolving forces and free body diagramsDistance, displacement and speedThe speed of sound, and the distance-speed-time equationVelocity and the distance-time relationshipAcceleration, deceleration and velocity-time graphsArea under a velocity-time graph, and the uniform acceleration equationNewton's First LawNewton's Second and Third LawsStopping distance and reaction timeFactors affecting braking distanceBraking force, deceleration and the dangers of stopping quicklyMomentum and its conservation
Magnetism and Electromagnetism
Particle Model of Matter
Forces
- 17 subtopics
- 45 things to know
- Physics Paper 2
What Forces covers
Forces is examined in Physics Paper 2. It covers scalars, vectors, forces and the resultant force, gravity, work done and energy transfer, stretching, compressing, and the spring constant, linear and non-linear extension, and work done on a spring, resolving forces and free body diagrams, distance, displacement and speed, the speed of sound, and the distance-speed-time equation, velocity and the distance-time relationship, acceleration, deceleration and velocity-time graphs, area under a velocity-time graph, and the uniform acceleration equation, Newton's First Law, Newton's Second and Third Laws, stopping distance and reaction time, factors affecting braking distance, braking force, deceleration and the dangers of stopping quickly and momentum and its conservation.
Where it is assessed
Physics Paper 2
Combined Science: Trilogy, Physics Paper 2: 1 hour 15 minutes, 70 marks, 16.7% of the qualification.
Check the AQA specification ↗The 17 subtopics
Each one has its own page.
- Scalars, vectors, forces and the resultant forceScalar and vector quantities and why velocity is a vector, representing vectors with arrows, contact and non-contact forces with examples of each, force as a vector and the pair of forces produced when two objects interact, and finding the resultant of forces acting along a straight line.Open →
- GravityWeight and why objects near the Earth have it, how weight depends on mass and gravitational field strength, the equation W = mg in words and symbols with calculations, the units of weight, mass and gravitational field strength, centre of mass, weight in direct proportion to mass, and measuring weight with a newtonmeter.Open →
- Work done and energy transferWhen work is and is not done on an object, the equation for work done in words and symbols with calculations, the units of work, force and distance, the joule and the newton-metre, the energy transfer when a crane lifts a load, and how work done against friction heats a car's brakes.Open →
- Stretching, compressing, and the spring constantThe forces that stretch, compress and bend objects, elastic and inelastic deformation, extension proportional to force up to the limit of proportionality, the equation linking force, spring constant and extension with its units, compressing rather than stretching, and the elastic potential energy stored as work is done on a spring.Open →
- Linear and non-linear extension, and work done on a springFinding the spring constant from force and extension or from a graph, what linear and non-linear mean, the energy stored in a stretched spring, and a method for investigating extension.Open →
- Resolving forces and free body diagramsThe forces on a book on a table and a boat crossing a lake, free body diagrams, balanced forces at a steady speed, the resultant of forces that do not act along one line, resolving a force into two components at right angles, and scale diagrams for finding a resultant and showing forces in balance.Open →
- Distance, displacement and speedDistance as a scalar and displacement as a vector with magnitude and direction, speed as a scalar that rarely stays constant, the factors affecting how fast people walk, run and cycle, typical speeds for walking, running, cycling, cars and aeroplanes, and other things whose speed varies.Open →
- The speed of sound, and the distance-speed-time equationA typical speed of sound in air, measuring speed from distance and time, the equation s = v t in words and symbols with its units and calculations, rearranging it for time, and calculating average speed for journeys in which the speed keeps changing.Open →
- Velocity and the distance-time relationshipVelocity as speed in a given direction and how it differs from speed, sorting scalars and vectors, changing velocity at constant speed in circular motion, distance–time graphs and finding speed from their gradient, a horizontal line for a stationary object, a curve for an accelerating one, and finding speed at an instant from a curved graph.Open →
- Acceleration, deceleration and velocity-time graphsThe equation for average acceleration with its units and the meaning of ∆v, deceleration and negative acceleration, estimating the accelerations of a sprinter and a car, finding acceleration from the gradient of a velocity–time graph, distance travelled from the area under it, and what horizontal and downward-sloping lines show.Open →
- Area under a velocity-time graph, and the uniform acceleration equationFinding distance from the area under a curved velocity-time line, the equation linking final velocity, initial velocity, acceleration and distance, free fall at 9.8 m/s², and terminal velocity.Open →
- Newton's First LawWhat Newton's First Law says about zero resultant force, what happens to stationary and moving objects when forces balance, why a car reaches a top speed, and what inertia means.Open →
- Newton's Second and Third LawsHow resultant force, mass and acceleration are linked, the units in F = m a, inertial mass, investigating force and acceleration with a trolley, and the equal and opposite forces of Newton's Third Law.Open →
- Stopping distance and reaction timeStopping, thinking and braking distance, how an increase in speed affects stopping distance, how reaction times vary and the things that lengthen them, measuring reaction time with a ruler-drop test and repeating it, and why a tired driver has a longer thinking distance.Open →
- Factors affecting braking distanceThe factors that lengthen braking distance, including icy and wet roads and worn brakes and tyres, whether heavy rain affects thinking or braking distance, leaving a bigger gap in icy weather, checking tyre tread, lower speed limits outside schools, and estimating braking distance when speed doubles or the road is wet.Open →
- Braking force, deceleration and the dangers of stopping quicklyThe energy transfer when brakes are applied, how speed affects the braking force needed, how braking force sets deceleration, and the dangers of overheating brakes, skidding and large forces on passengers.Open →
- Momentum and its conservationMomentum as mass times velocity in words and symbols with its units and calculations, the momentum of a stationary object, conservation of momentum in a closed system, and explaining skaters pushing apart, colliding trolleys that join together and a recoiling rifle.Open →
What you need to know
Answer each one before you reveal it.
Your recallNot started
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Describe the difference between contact and non-contact forces, give examples of each, and name the force a table exerts on a book.
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Use Newton's First Law to explain why a car reaches a top speed, why a cyclist who stops pedalling slows, and when velocity changes.
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What is the weight of an object?
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When is work done on an object?
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Name the force that stretches a spring when a mass is hung from it.
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What two measurements are needed to find the spring constant of a spring?
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Describe the forces acting on a book resting on a table.
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What does the quantity distance tell you about the movement of an object?
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Which two measurements must be taken in order to calculate the speed of a moving object?
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State the word equation for the average acceleration of an object.
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On a velocity–time graph each square represents 2 m/s along one side and 1 s along the other. What distance does one square represent?
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Which three quantities are linked by Newton's Second Law?
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For a given braking force, how does an increase in speed affect the stopping distance?
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Name two general kinds of factor that can lengthen the braking distance of a vehicle.
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Why do the brakes of a vehicle get hot when it stops?
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Which two quantities are multiplied together to give the momentum of a moving object?
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What does a scalar quantity tell you about?
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An astronaut takes a toolbox to the Moon. Explain why its weight changes.
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What two quantities must be known to calculate the work done by a force?
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Give an example of forces compressing an object.
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Describe the difference between a linear and a non-linear relationship between force and extension.
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Describe the four forces acting on a boat travelling across a lake.
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Why is distance classed as a scalar quantity?
Numbers
A cyclist rides at a constant 6 m/s for 40 s. Calculate the distance travelled.
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What is meant by the velocity of an object?
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In what unit is acceleration measured, and what symbol represents it?
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State in words the equation linking final velocity, initial velocity, acceleration and distance for uniform acceleration.
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When all the forces acting on an object are balanced, what is the size of the resultant force?
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The resultant force on an object is doubled while its mass stays the same. What happens to its acceleration?
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State the range of typical values for human reaction time.
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Explain why the braking distance of a car is longer on an icy road.
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How does the speed of a vehicle affect the braking force needed to stop it within a fixed distance?
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State the word equation that defines momentum.
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Name three quantities that are scalars.
Numbers
State the equation used to calculate the weight of an object, in words.
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State the equation for work done, in words.
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Give an example of forces bending an object.
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What does a large spring constant tell you about a spring?
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A car travels along a level road at a steady speed. Explain what this tells you about the forces on it.
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What two pieces of information together make up a displacement?
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State the word equation linking distance travelled, speed and time.
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Why is velocity classed as a vector quantity?
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What word describes an object that is slowing down?
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Write the uniform acceleration equation using the symbols v, u, a and s.
Take Forces further
The same content, four other ways.
Commonly confused
Pairs that lose marks when they are blurred together.
Scalar vs Vector
Scalar: a quantity with magnitude only. Vector: A quantity with both a magnitude and a direction.
Distance vs Displacement
Distance: how far an object has moved, with no direction. Displacement: Straight-line length from start to finish, with its direction.
Thinking distance vs Braking distance
Thinking distance: how far the vehicle travels during the driver's reaction time. Braking distance: How far the vehicle travels while the brakes are acting.
Questions from this topic
Each one with the model answer underneath.
- 1
What does a scalar quantity tell you about?
Model answer
A scalar quantity has magnitude, or size, only.
- 2
Name three quantities that are scalars.
Model answer
Mass, speed and energy are all scalar quantities.
- 3
What two things does a vector quantity have?
Model answer
A vector quantity has a magnitude and an associated direction.
- 4
Explain why velocity is a vector but speed is a scalar.
Model answer
Velocity states a direction as well as a size, while speed states only a size.
- 5
How is a vector quantity represented on a diagram?
Model answer
It is represented by an arrow.
- 6
What does the length of an arrow representing a vector show?
Model answer
The length shows the magnitude of the vector quantity.
What is inside Levo
Six ways to work the same material.
Forces revision questions
- What does Forces cover in AQA GCSE Combined Science Physics?
- 17 subtopics: scalars, vectors, forces and the resultant force, gravity, work done and energy transfer, stretching, compressing, and the spring constant, linear and non-linear extension, and work done on a spring, resolving forces and free body diagrams, distance, displacement and speed, the speed of sound, and the distance-speed-time equation, velocity and the distance-time relationship, acceleration, deceleration and velocity-time graphs, area under a velocity-time graph, and the uniform acceleration equation, newton's first law, newton's second and third laws, stopping distance and reaction time, factors affecting braking distance, braking force, deceleration and the dangers of stopping quickly and momentum and its conservation. Each one has its own page with questions and model answers.
- How is Forces organised?
- By the AQA 8464 specification, subtopic by subtopic, so it matches the order you are taught it in.
Every question in Forces, 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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