energy, power + effiency

• The 8 energy stores are: Chemical, Elastic, Electrostatic, Gravitational Potential, Kinetic, Magnetic, Nuclear and Thermal
• The conservation of energy says energy cannot be created nor destroyed, it can only be shifted from one store to another
• The 4 energy shifts are: Mechanical, Electrical, Radiation and Heating
• The chemical energy store can be found in fossil fuels
• The kinetic energy store can be found in moving objects
• Magnetic energy is stored by magnets or magnetic materials
• Gravitational potential energy is stored when an object has height above ground level
• Nuclear energy is released during nuclear reactions such as fission and fusion
• The thermal energy store can be found in warm objects
• The elastic energy store can be found in a stretched or compressed spring
• Electrostatic energy is stored in two separated electric charges that are attracting or repelling
• Effiency is a measure of useful power output divided by total power input
• Power is energy transferred divided by time or work done divided by time
• The symbol equations for power are

  P = E / t or P = W / t
• Gravitational potential energy = mass x gravitational field strength x height
• The equation for gravitional potential energy in symbols is: E_p = mgh
• Kinetic energy = 0.5 x mass x speed squared
• The equation for kinetic energy in symbols is E_k = 1/2mv^2
• Work done = force x distance moved in a given direction
• The equation for work done in symbols is W = Fs
• Elastic potential energy = 0.5 x spring constant x extension squared
• The equation for elastic potential energy in symbols is E_e = 1/2ke^2