Flashcards in Energy Deck (37)
What are the stores of energy? (8)
What is kinetic energy?
energy that moving objects have
What is gravitational potential energy?
energy stored by objects that are raised off the ground
the higher the object is lifted, the more gravitational potential energy it has
What is elastic potential energy?
energy transferred by stretching or squashing an object
What is specific heat capacity?
the amount of energy needed to raise the temperature of 1kg of a substance by 1°C
What is the principle of the conservation of energy?
Energy can be transferred or stored but can never be created or destroyed.
What is power?
the rate of energy transfer
What is conduction?
the process where vibrating particles transfer energy to neighbouring particles usually in solids
energy transferred to an object by heating is transferred to the thermal store of the object
this energy is shared across the kinetic energy stores of the particles in the object
the particles being heated vibrate more, causing them to collide with eachother
these collisions cause energy to be transferred between the particle's kinetic energy stores
(this continues through the object until the energy is transferred to the other side of the object)
What is thermal conductivity?
a measure of how quickly energy is transferred through a material by conduction
What is convection?
the process where energetic particles move away from hotter regions to cooler regions in liquids and gases
energy is transferred by heating the thermal store of the liquid/gas
when a region of the liquid/gas is heated, the particles gain energy and move faster so that the space between the individual particles increase, causing the density of that region to decrease
the warmer, less dense region will then rise above the cooler, denser regions
if there is a constant heat source, a convection current is created and this becomes a cycle
What is the difference between renewable and non-renewable energy resources?
non-renewable energy resources will eventually run out but renewable resources won't
What resources are non-renewable?
fossil fuels (eg. coal, oil and natural gas)
nuclear fuel (eg. uranium and plutonium)
What resources are renewable?
What energy sources are used for transport?
petrol and diesel come from oil (non-renewable)
What energy sources are used for heating?
electricity from renewable sources
What are the advantages of wind power?
-no permanent damage to the landscape
-minimal running costs (no fuel costs)
What are the disadvantages of wind power?
-spoil the view
-can be noisy
-reliant on weather (no electricity produced when there's no wind)
-initial cost can be high
What are the advantages of solar power?
-reliable (in some places)
-low running costs
What are the disadvantages of solar power?
-high initial costs
-only reliable in day time/when there's sun
-usually only generate energy on a small scale
How does geothermal power work?
cold water is pumped down underground
hot rocks underground heat the water (boil it)
steam is pumped up to power a turbine and then condensed to go back down to be heated again
the turbine turns a generator, which creates power for the national grid
What are the advantages of geothermal power?
-has very few environmental problems
What are the disadvantages of geothermal power?
-only suitable in volcanic areas (limited by location)
-high cost of building a power plant compared to the energy it produces
How does hydroelectric power work?
water is stored in a dam
when the valley (made by the dam) floods, the water powers turbines that turn a generator to produce electricty
What are the advantages of hydroelectric power?
-can provide an immediate response to an increased demand in electricity
-low running costs and no fuel costs
What are the disadvantages of hydroelectric power?
-don't look appealing when they dry up
big impact on environment, flooding causes:
-loss of habitat
-rotting vegetation (which releases methane and carbon dioxide)
How does wave power work?
As waves move in, air is forced out, which causes a turbine and therefore generator to turn
What are the advantages of wave power?
-low running costs and no fuel costs