energy Flashcards
what is the law of conservation of energy?
energy before=energy after
shows energy cannot be created or destroyed only transferred and changed from one form to another
what is a fuel?
a fuel is something you can burn and get energy from
what is the combustion equation?
fuel +oxygen=carbon dioxide +oxygen
what is combustion?
the process of burning something
what are the 10 differennt types of stored energy?
thermal energy-
more energy when hot than cold, amount of j depends on the temp of things
kinetic energy-
more energy the faster you move e.g run, amount of energy depends on the speed of an object
gravitational potential-
more energy when placed on a higher shelf, amount of energy depends on height of object
chemical energy or chemicall stored energy-
transfer of energy from chemicals occurs due to chemical reaction, amount of energy depends on the chemical reaction
elastic potential energy-
stretched or squashed object
more energy in its elastic stored energy
amount depends on extension or compression
electric energy
sound energy
nuclear energy
light energy
in most situations which energy is the most wasted?
thermal energy is the most wasted energy and builds up a lot in our enviroment
to find the efficiency and efficientness of energy you pay you do:
useful energy output divided by total energy input
and then multiply the answer by 100 to egt it to
a washing machine has a total energy of 150j
heat-46j-wasted
light-59j
sound-45
find its efficiency:
the useful energy add it together
59 plus 45=104j
total energy-150j
104 divided by 100=0.6933 times 100=69.3percent efficient
thermal energy-
the energy stored in an object
temperature-
the measure of how hot or cold an object is
hotter the object..
the more energy it has in its thermal store
bigger object mass means
more energy particles stored inside
thermal energy is dependant on 3 things:
the mass of substance-m
specific heat capacity-c
temperature change- delta triangle
the equation for what the temperature of an object depends on
q=m times c times delta triange
what does the q,m,c and triangle stand for
q-thermal energy
m-mass of substance
c-specific heat capacity
triangle-temperature change
