GCSE›AQA GCSE Physics›Mind mapsEnergy Stores and TransfersAQA GCSE Physics: Mind mapStudy pack PDFAlso for this subtopic:Revision notesFlashcardsSubtopic testCover factsSystems and storesA system is an object or group of objectsStores: kinetic, thermal, gravitational, elastic, chemical, nuclearA change in a system transfers energy between storesTotal energy before and after is always the sameWays to transferHeatingWork done by a forceWork done when a current flowsEveryday changesThrown upwards: kinetic falls, gravitational risesHits obstacle: kinetic falls, thermal and sound riseCar braking: kinetic falls, brakes gain thermalBoiling water: chemical falls, water's thermal risesEnergy storesand how they transferJEkE_kEkEpE_pEpWStore equationsKinetic: Ek=12mv2E_k = \frac{1}{2}mv^2Ek=21mv2Elastic: Ee=12ke2E_e = \frac{1}{2}ke^2Ee=21ke2Gravitational: Ep=mghE_p = mghEp=mghThermal: ΔE=mcΔθ\Delta E = mc\Delta\thetaΔE=mcΔθSpecific heat capacity: energy to warm 1 kg by 1°CPowerPower is the rate of energy transferP=EtP = \frac{E}{t}P=tE and P=WtP = \frac{W}{t}P=tWMeasured in watts (W)Same energy in less time means more powerExam tipsName the store that decreases and the ones that increaseElastic equation needs limit of proportionality not exceededDo not mix up specific heat capacity and latent heat