energy breakdown

energy

ability to do work (measured in joules J). an object/organism uses energy when it performs work, which is defined as exerting a force over a distance to move an object. conversely, an object gains energy when work is performed on it.

kinetic energy

associated with movement. its magnitude depends on two factors: velocity and mass. includes: mechanical, electrical, heat, sound and light energy

mechanical (motion) energy

the movement of substances/objects from one location to another

electrical energy

created by electrons moving in one direction through a closed circuit

heat (thermal) energy

energy in transit moving from a ‘hot’ object to a ‘cooler’ one.

sound energy

energy contained in air when it is vibrating

light (radiant) energy

energy from light that is part of the electromagnetic spectrum

potential energy

stored energy - related to an object’s position. forms include - gravitational potential energy, chemical energy, elastic potential energy

gravitational potential energy

energy stored due to an objects height and weight

chemical energy

energy stored in the bonds between atoms that hold molecules together

elastic potential energy

energy stored in elastic materials by either stretching or compressing them

energy transfers

energy passes from one object/place to another without changing form

energy transformation

energy changes from one form into one or more different forms

efficiency

measures how much energy is successfully converted into the desired form. no real device is 100% efficient - some energy is always transformed into heat or sound during transfers and transformation. this doesn’t break the law - all input energy is still accounted for.

input vs output

input energy is the energy supplied to a device, while output energy is the energy that comes out

useful output energy

output energy put to its intended use

wasted output energy

output energy not used for the intended purpose - commonly heat/sound

high efficiency

indicates that a large proportion of the input energy is converted into useful output

low efficiency

indicates that much of the energy is lost as waste