BRAINCAKEEnergy
Revision notes for Energy in AQA Physics (8463). Every lesson in BrainCake comes with R.E.C.I.P.E. recall steps, a quick check and spaced reviews.
- Energy stores and systemsA system is an object or a group of objects.
- Changes in energyThe kinetic energy of a moving object is Ek = 0.5 × m × v2, where m is mass in kilograms and v is speed in metres per second.
- Energy changes in systemsWhen a substance is heated, energy is stored in its thermal store and its temperature rises.
- PowerPower is the rate at which energy is transferred, or the rate at which work is done.
- Energy transfers in a systemEnergy can be transferred usefully, stored or dissipated, but it cannot be created or destroyed.
- EfficiencyNo device transfers all of its input energy usefully, so we measure how good it is using its efficiency.