Energy Flashcards
what are the energy stores?
chemical , elastic potential , gravitational potential , nuclear , kinetic , magnetic , thermal , electrostatic
what are the energy pathways?
mechanical , electrical , heat , radiation
what is thermal conductivity?
a measure of how well a materical conducts energy when it is heated
what is energy efficiency?
the amount if energy which is wasted
how do power stations work?
fuel is used to heat water which produces steam
what are some renewable energy resources?
hydroelectricity, geothermal , tides , sun
what is specific heat capacity?
the energy required to raise one kilogram (kg) of the material by one degree Celsius (°C)
power
= energy transferred / time
kinetic energy
= 0.5 x mass x velocity2
gravitational potential energy
= mass x gravitational field strength x height
specific heat capacity
heat energy = mass x specific heat capacity x change in temp
define power
power is the amount of energy transferred or converted per unit time
elastic potential energy
elastic energy = 1/2 x spring constant change in position squared
what is the law of the conservation of energy?
the total energy of an isolated system remains constant
what is the definition of dissipation of energy?
Any energy that is not transferred to useful energy stores is said to be wasted because it is lost to the surroundings
how to reduce unwanted energy transfers??
insulation
what does the higher thermal conductivity of a material do
a higher rate of energy transfer by conduction
efficiency in terms of power
useful power out / total power in
efficiency in terms of energy
usual energy out / total energy in
what are the main energy sources available
fossils fuels, nuclear fuel, biofuel, wind, hydroelectricity, geothermal, tides, sun and water waves
what is renewable energy and what are some examples?
energy that is collected from resources that will never run out or which are replaced by nature in less than a human lifetime
hydroelectric, wind, solar, tidal, wave, geothermal, biomass
how is internal energy effected by changing temperature and changing state?
temperature : particles speed up and gain kinetic energy
changing state : The electrostatic potential energy of the molecules increases, The bonds between molecules break and the molecules move further apart
what does work done cause against the frictional forces acting on an object?
a rise in the temperature of the object
