Topic P1 Energy Flashcards
state the ways that energy is transferred between stores
- thermal
- kinetic
- gravitational potentional
- elastic potential
- chemical
6.
what are closed systems
systems where neither matter nor energy can enter or leave
-the net change in total energy is always zero
how is energy transferred by heating
-e.g boiling water in kettle
-energys transferred to the water by heating into the waters thermal energy store causing temperature of the water to rise
state what happens when a ball goes upwards
-inital force exerted by a person to throw the ball does work
energy transfer: from chemical energy store of persons arm to kinetic
name the energy store that happens when dropping a ball
goes from gravitational potential energy store to kinetic energy store
state what happens when a car brakes
friction between the wheels and car brakes does work as it slows down
-causes energy transfer from wheels kinetic energy to thermal
state what would happen in a collision between a car and stationary object
-energys transferred from the cars kinetic energy store to other stores
-some energys also transferred away by sound waves
state the unit for kinetic energy
-joules
state when kinetic energy is to the store what happens
when its transferred away
-to the store, an object speeds up
-transferred away from the store when an object slows down
the greater the mass
the faster its going
-more energy will be
gravitational field strength
N/kg
whats speed squared measured in
m/s squared
what happens when falling objects transfer energy
-when something falls, energy from its gravitational potential energy is transferred to its kinetic energy
-no air resistance for falling objects
whats mass measured in
kg
height measurements
metres
what does stretching do to an objects
transfers energy to its elastic potential energy store
what is work done measured in
joules
what is specific heat capacity
amount of energy in joules needed to raise the temperature of 1kg of material by 1degrees
describe energy transfers for closed for closed systems
-energy transfers occur between the components of the system, but the total energy within the system remains constant, as no energy is lost to or gained from the surroundings.
specific heat capacity unit
J/kg degrees
what is dissipated energy
sometimes called wasted energy
-energys stored in a way that is not useful
what is the conservation of energy principle
that energy can be transferred usefully, stored or disspiated but can never be created or destroyed
what is power
rate of energy transfer or the rate of doing work
what is lubrication used for
reducing frictional forces
-and whenever something moves theres usually 1frictional force acting against it
-causes energy in systems to be dissipated
what is power measured in
watts
-1watt- 1joule of energy transferred per second
state what happens when an objects heated
-energy is transferred to the kinetic energy stores of its particles
-this causes particles to vibrate more and to collide
-during these collisions energys transferred between the particles kinetic energy stores, CONDUCTION
-if particles are free to move, particles more quicker and it means the space between individual particles increases too
what is the difference between conduction and convection
-conduction transfers heat through direct contact between particles in a solid, whereas
-convection transfers heat through the movement of fluids (liquids or gases)
2ways to prevent energy losses through heating
-have thick walls, made from material with low thermal conductivity
-use thermal insulation
examples of thermal insulation
- cavity walls, made up of inner and outer wall with an air gap in the middle filled with foam. the gap reduced energy transfer
- loft insulation, reduces convection currents
- double-glazed windows, air gap between 2 sheets of glass to prevent energy transfer
state 3 ways to improve efficiency of energy transfers
- insulating objects
- lubricating them
- making them more streamlined
state 2 non renewable energy sources
- fossil fuels
- nuclear fuel
3main fossil fuels
- coal
- oil
- natural gas
state 3things about non-renewable energy sources
- they will all run out one day
- all do damage to the environment
- provide most our energy
state 4 renewable energy sources
- geothermal
- wind
- water waves
- hydro-electricity
state 3 things about renewable energy resources
- they will never run out and the energy can be renewed
- most of them do damage to the environment but in less bad ways
- trouble is they do not provide much energy and are unreliable as they depend on weather
state non renewable and renewable examples used for transport
NON- petrol
-diesel
-coal used in steam trains
RENEW- vehicles used on pure bio-fuels
state the non-renewable energy resources used for heating
-natural gas, used to heat water which is then pumped into radiators throughout homes
-coal is burnt in fireplaces
-electric heaters
state renewable energy resources
-a geothermal heat pump
-solar water heaters which use the sun to heat water, that is then pumped into radiators in buildings
-burning bio-fuel or using electricity generated from renewable resources
state what renewable energy resources will not run out
-wind
-solar
-geothermal
state how wind power is generated
by wind turbines
-involves putting lots of wind turbines up in exposed places e.g coasts
-each turbine has a generator inside and the rotating blades turn it and produce electricity
what are the disadvantages of wind turbines
-spoil views as you need 1500
-can be very noisy
-turbines may stop when wind stops
-inital costs are high
advantages of wind turbines
-no permanent damage to landscape
-renewable
-proudce electricity 75-80% of time
-no fuel costs and minimal running costs
explain why solar cells are fairly reliable
-consistent energy production with components that rarely experience failure
-inital costs are high but after energy is free and running costs are small
-only used in daytime
where is geothermal power used
-in volcanic areas where hot rocks lie near the surface
-free energy which is reliable
-can be used to generate electricity and heat buildings directly
state the problem of geothermal power
-there isn’t many suitable locations for power plants
-cost of building plant is high compared to energy thats produced
what is hydro-electric power used for
-falling water
-builds a big dam and waters allowed out through turbines
advantages and disadvantages of hydro-electric power
ADV
-provides immediate response to increased demand for electricity
-reliable except in times of drought
-no fuel costs, minimal running
DISADV
-big impact on environment due to flooding of valleys
-possible loss off habitats
-inital costs are high
wave power adv and disadv
adv
-no pollution
-no fuel costs
-minimal running costs
disadv
-disturbs habitats
-unreliable as waves die out when wind drops
-hazard to boats
how to use tides
-build a tidal barrage
-big dams built across river estuaries with turbines in them
-as the tide comes in it fills estuary and waters allowed out through turbines at controlled speeds
adv and disadv of tidal barrages
ADV
-no pollution
-reliable
-no fuel costs and minimal running costs
DISADV
-prevents access to boats
-altering habitats
-height of tide is variable, so lower tides produce less energy
state examples of renewable energy resources
-wind power
-solar cells
-geothermal power
-wave power
state the energy source bio-fuels uses
-made from plant and waste and are burnt to produce electricity in the same way as fossil fuels
adv and disadv for bio-fuels
adv
-reliable
-renewable energy resource
disadv
-cannot respond to immediate energy demands
-cost to refine them is very high
-large areas have to be cleared to grow bio-fuels
give 2ways an environment can be damaged when using fossil fuels
-releases carbon dioxide, which traps heat and causes Earth’s temperature to rise.
-Greenhouse gas emissions cause global warming.
3reasons why renewable energy sources are limiteed
-by reliability
-money
-politics
