GCSE Physics resources
AQA GCSE Energy
Choose an equation from the physical change, convert every quantity to SI units and show the substitution.
Start here
Match the equation to the physical change: speed for kinetic energy, height for gravitational potential energy, extension for elastic energy, force and distance for work done, and time for power. Convert units before substitution.
Core learning content
Start with this short teaching sequence for Energy Calculations and Power. Read the model, use the visual, then test your recall before moving into examples and exam practice.
Match the equation to the physical change: speed for kinetic energy, height for gravitational potential energy, extension for elastic energy, force and distance for work done, and time for power. Convert units before substitution.
The words in the question choose the model. Height points to gravitational potential energy, speed to kinetic energy, extension to elastic potential energy and time to power. Write quantities in SI units before putting numbers into an equation.
Choose a relationship because of the physical change in the question, not because it is familiar. Kinetic energy: Eₖ = ½mv² (J, kg, m/s). Gravitational potential energy: Eₚ = mgh (J, kg, N/kg, m). Elastic potential energy: Eₑ = ½ke² (J, N/m, m). Keep the unit next to each value while you substitute.
Underline the changing quantity, write the equation, substitute with SI units, calculate and check whether the scale and unit make sense. Before writing, underline the command word and identify the information that matters. Keep a calculation as equation, substitution and answer with unit; keep an explanation as a linked chain using because, so or therefore. Finish by checking that the final sentence answers the exact context in the question and that the number, direction or conclusion agrees with the evidence given.
Retrieval practice
Answer without looking back first. The feedback explains the model, so a wrong answer still helps you learn.
Mini quiz 1
Mini quiz 2
Mini quiz 3
Try it
Which physical change should decide the equation you use?
What to notice: the readout and written explanation remain available if you do not use the controls.
Worked examples
Cover the answer, attempt the method and then compare your physics language as well as the number.
E = 78.4 J, so the box gains 78 J to two significant figures.
Eₖ = 0.5 × 0.80 × 5.0² = 10 J.
P = 400 W.
Misconception clinic
Each of these is tempting because it sounds almost right. Replace it with the precise physics before you meet it in a question.
Independent practice
Use the working space first. Reveal the guidance only after you have committed to an answer, then improve the exact part that would gain the next mark.
Eₖ = ½mv² = 0.5 × 1.5 × 4.0² = 12 J.
E = mgh = 0.20 × 10 × 3.0 = 6.0 J.
Eₑ = ½ke² = 0.5 × 200 × 0.10² = 1.0 J.
Convert 5.0 min to 300 s. E = Pt = 60 × 300 = 18 000 J.
It transfers energy to the water at a greater rate.
Check mass is in kg and height is in m; g should be in N/kg.
Questions pupils ask
Energy questions become easier when you name the system, track the stores that change and identify the transfer pathway. Then choose an equation only when the physical change requires it.
Read the snapshot, attempt the worked examples without looking, complete the mini quizzes and then use the practice questions to check your wording and method.
Next step
Physics sticks when you move between explanation, retrieval and application.