GCSE Physics resources
AQA GCSE Forces
Use a trolley and light gates or video timing to measure speed and acceleration. Reduce friction where possible, repeat readings and keep the mass or force controlled according to the variable being investigated.
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Use a trolley and light gates or video timing to measure speed and acceleration. Reduce friction where possible, repeat readings and keep the mass or force controlled according to the variable being investigated.
Before you revise
Choose an answer from memory. Your result tells you what to watch for in the guide.
Core revision guide
Acceleration Required Practical questions become manageable when the central model, evidence and exam method are kept together. Read the explanation, test the misconception and then apply the idea without looking back.
Use a trolley and light gates or video timing to measure speed and acceleration. Reduce friction where possible, repeat readings and keep the mass or force controlled according to the variable being investigated.
Acceleration is a change in velocity per second. Light gates can measure instantaneous speed without human reaction time; a velocity-time graph then gives acceleration from its gradient. Repeat readings and control the variable not under investigation so that a trend is meaningful.
Acceleration: a = Δv ÷ t (m/s², m/s, s). Newton’s second law: F = ma (N, kg, m/s²). Choose each relationship from the physical change described, convert quantities into compatible units and keep the unit beside the final answer.
Misconception clinic
Read each belief, say what is wrong with it, then compare your correction.
Tempting idea: Using distance-time gradient as acceleration.
Use instead: Use a trolley and light gates or video timing to measure speed and acceleration. Reduce friction where possible, repeat readings and keep the mass or force controlled according to the variable being investigated.
Tempting idea: Changing mass and force together unintentionally.
Use instead: Acceleration is a change in velocity per second. Light gates can measure instantaneous speed without human reaction time; a velocity-time graph then gives acceleration from its gradient. Repeat readings and control the variable not under investigation so that a trend is meaningful.
Tempting idea: Using reaction-time measurements when light gates are available.
Use instead: Describe timing, the independent variable, controlled factors, graph choice and how the setup reduces random or systematic error.
Retrieval practice
Worked examples
These examples expose the difference between a secure measure acceleration from motion data method and the common error “Using distance-time gradient as acceleration.”.
a = 2.0 m/s².
Light gates give more precise velocity/timing measurements than a handheld stopwatch.
Vary the driving force, calculate acceleration from motion data, and keep trolley mass, track angle and friction as constant as possible.
Exam precision
Do this: Describe timing, the independent variable, controlled factors, graph choice and how the setup reduces random or systematic error.
Independent practice
Write an answer before opening the marking guidance. Then edit the exact phrase or step that would gain the next mark.
Marking guidance: Award one mark for the precise statement shown in the model answer.
Model answer: a = change in velocity ÷ time.
Marking guidance: Award one mark for the precise statement shown in the model answer.
Model answer: Acceleration.
Marking guidance: 2 marks are available for relevant, linked physics points that match the model answer.
Model answer: For example: total mass, track angle, surface/friction and starting position.
Marking guidance: 2 marks are available for relevant, linked physics points that match the model answer.
Model answer: To calculate a mean and identify anomalous results.
Marking guidance: Award one mark for the precise statement shown in the model answer.
Model answer: Acceleration.
Marking guidance: Award one mark for the precise statement shown in the model answer.
Model answer: Use a smooth/level track or a runway with low-friction wheels and account for friction consistently.
Questions pupils ask
Use a trolley and light gates or video timing to measure speed and acceleration. Reduce friction where possible, repeat readings and keep the mass or force controlled according to the variable being investigated.
Using distance-time gradient as acceleration. Acceleration is a change in velocity per second. Light gates can measure instantaneous speed without human reaction time; a velocity-time graph then gives acceleration from its gradient. Repeat readings and control the variable not under investigation so that a trend is meaningful.
Useful next steps