Physics paper 1

Energy:

Energy stores - thermal, kinetic, gravitational potential, elastic potential, chemical, magnetic, electrostatic, and nuclear.

When a system changes, energy is transferred by heating or by doing work.

Kinetic energy = 1/2 x mass x velocity (squared)

Gravitational potential energy = mass x gravitational field strength x height

Elastic potential energy = 1/2 x spring constant x extension (squared)

Specific heat capacity is the amount of energy needed to raise the temperature of 1kg of a substance by 1 degree. 

Change in thermal energy = mass x specific heat capacity x temperature change

Conservation of energy principle: Energy can be transferred usefully, stored or dissipated, but never be created or destroyed. 

Power = Energy transferred or work done / time

Conduction (in solids) is the process where vibrating particles transfer energy to neighbouring particles by heating.

Convection (in liquids and gases) is where energyetic particles move away from hotter to cooler regions. Radiators create convection currents.

Lubrication reduces frictional forces. 

Insulation reduces the rate of energy transfer by heating. In houses this can be done through…