energy resources and transfers

1- kinetic

2- thermal

3- chemical

4- GPE

5- elastic potential

6- electrostatic

7- magnetic

8- nuclear

what are the eight types of energy stores?

anything moving has energy in its kinetic energy store

what happens in kinetic?

any object- the hotter the more energy it has in it's store

what happens in thermal?

anything that can release energy by a chemical reaction e.g food and fuels

what happens in chemical?

anything that is in a gradational field (anything that can fall)

what happens in GPE?

anything stitched like springs and rubber bands

what happens in elastic potential?

two charges that attract or repel

what happens in electrostatic?

two magnets that attract or repel

what happens in magnetic?

atomic nuclei releases energy from this store in nuclear reactions

what happens in nuclear?

1- mechanically

2- electrically

3- by heating

4- by radiation

what are the four main ways that energy can be transferred between?

an object moving due to a force acting on it e.g push or pull

what happens in mechanically?

a charge moving through a potential difference e.g charges moving through a circuit

what happens in electrically?

energy transferred from a hotter object to a cooler object

what happens in heating?

energy transferred by light/sound waves

what happens in radiation?

energy cannot be created or destroyed but it can be transferred from one store to another

what is the principle of conservation of energy?

what is efficiency defined as?

radiation, conduction and convection

what are the 3 ways energy can be transferred by heating?

the transfer of energy by heating by infrared electromagnetic waves

what is thermal radiation?

the main form of energy transfer by heating in solids

what is conduction?

the main form of energy transfer by heating in liquids and gases

what is convection?

emission of electromagnetic waves

what does thermal radiation involve?

infrared radiation, consists of electromagnetic waves of different frequencies .

what can thermal radiation also be called as?

emit and absorb infrared radiation

what do all objects continually do?

it emits more radiations that it abosrbs as it cools down

if an object is hotter than its surrounding what happens?

it absorbs more radiation that it emits as it warms up

if an object is cooler than its surrounding what happens?

the particles are held tightly together. when one particle vibrates, it collides with other particles nearby.

is a solid is heated what happens?

the process where vibrating particles transfer energy from their kinetic energy store to the kinetic energy stores of neighbouring particles.

definition of thermal conduction?

convection occurs when the more energetic particles move from the hotter region to the cooler region and transfer energy only in liquids and gases.

definition of convection?

what happens in an immersion heater?

in roundish or squarish containers because they allow the convection current to work best.

where is convection most efficient?

coloured crystals:

1- place some purple potassium permanganate crystals in a beaker of cold water. put the crystal to one side of the beaker.

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2- use a bunsen burner and gently heat the side of the beaker with the crystals at the bottom.

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3- as the temperature of the water increases the crystals with dissolve forming a bright purple solution.

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4- it will then be carried by convection.

what is a practical that you can see convection currents?

how well it can transfer energy by conduction.

what does the thermal conductivity of an object describe?

use materials with low thermal conductivity

if you want to reduce energy transfers by conduction what should you do?

stop the fluid from moving and prevent convection currents forming

if you want to reduce energy transfers by convection what should you do?

object should be desgined with a surface that is a poor emitter

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clothes, blankets and foam cavity wall insulation all work by trapping pockets of air.

air cannot move so energy conducts slowly and material which has low thermal conductivity.

if you want to reduce energy transfers by insulation what should you do?

black is better than white

dull is better than shiny

what colours absorb and emit IR radiation better than others?

energy transferred

what does work done mean?

when a force moves an object through a distance, work is done on the object and energy is transferred.

definition of work done

you are doing work against frictional forces. energy is being transferred to the kinetic energy store because the object starts moving, and some is being transferred to the thermal energy store due to friction. temp will increase. ( e.g rubbing your hands together will warm them up).

what happens when you push something along a rough surface?

formula for work done

power is a measure of how quickly work is being done

power is the rate at which energy is transferredpow

definition of power

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power formula

kinetic energy formula

GPE formula

non renewable

what type of energy resource will run out one day?

non renewable

what type of energy resource will do damage to our planet?

non renewable

what type of energy resource provides most of our energy?

1- coal

2- natural gas

3- oil

4- nuclear fuels

what are example of non renewable resources?

steam

what do most power stations use to drive a turbine?

from the 4 non renewable resources In big power station.

where is our electricity generated?

1- as the fossil fuel burns in oxygen the energy in it’s chemical energy store is transferred to the thermal energy store of the water by heating.

2- water boils to form steam. the steam turns the turbine transferring energy mechanically the kinetic energy store of the turbine.

3- as the turbine rotates also the generator which produces an electric current. It transfers the energy electrically away from power station to natural grids to homes.

how does a power station work?

1- burning them releases lots of energy quite cheap

2- energy from fossil fuels don’t rely on weather - RELIABLE ENERGY SOURCE

3- lots of power stations for fossil fuels dont need to spend more money or new technology to use them

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what are the advantages of fossil fuels?

1- fossil fuels release carbon dioxide into atmosphere when burned. contributes to global warming and climate change.

2- burning COAL & IRON releases sulfur dioxide, causes acid rain. acid rain damages trees and soils, huge impact on wildlife.

3- they will eventually run out

what are the disadvantages of fossil fuels?

use energy from the kinetic energy store of moving air to generate electricity. the wind turns the blades, which turns a generator inside of it.

how do wind turbines work?

* quite cheap to run
* very tough and reliable
* renewable will never run out
* doesn’t produce any polluting waste

what are the advantages of wind turbines?

* they spoil the view. many of them need.
* - very noisy can disturb people
* expensive to set up especially out at sea

what are the disadvantages of wind turbines?

heat from underground

what is geothermal power?

* only possible where hot rocks lie near the surface
* water is pumped in pipes down to the hot rocks and forced back due to pressure to turn a turbine and drive a generator.
* energy transferred from thermal to kinetic to generate electricity

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how does geothermal power work?

* used to heat building directly
* free renewable energy no environmental problems.

what is geothermal energy used for?/advantages

* cost of drilling down several km
* cost of building a power plant

what are the disadvantages of geothermal power process?

solar cells

what type of cells can you capture the sun’s energy?

photocells

* use energy from the sun to directly generate electricity.
* generate direct current

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what is the other name for solar cells and how do they work?

* sun provides a renewable energy resource
* no pollution involved
* when there is no sunlight cells can be linked to rechargeable batteries to create a system that can store energy from the day to use at night

what are the advantages for using solar cells?

* expensive
* not practical to connect them to national grid- very expensive
* they can only generate electricity when there is enough sunlight- problem at night.

what are the disadvantages for using solar cells?

* simpler than solar cells
* black water piper inside a glass box.
* glass allows energy from sun, absorbed by black pipes and heats up water
* cost money to set up but they are renewable and free after
* used for small scale energy production

what are solar water heating panels?

* generate energy when the tide goes in and out
* big dams built across rivers, with turbines inside.
* as the tide comes in it fill us the estuary and then the water can be allowed out through turbines at a controlled speed

how do tidal barrages work?

* no pollution
* renewable

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what are the advantages of tidal barrages?

* preventing boats
* spoiling view
* altering habitat of wildlife
* lower tides will provide less energy than higher ones
* initial costs are high

what are the disadvantages of tidal barrages?

* requires flooding of a valley by building a big dam
* rainwater is caught and allowed out through turbines
* energy transferred is GPE-KE to generate electricity h

how does hydroelectric power work?

* renewable
* no pollution
* immediate response to increase in demand

what are the advantages of hydroelectric power?

* flood valley
* rotting vegetation releases carbon dioxide and methane
* loss of habitat for some species
* dont look very good when they dry up
* costs are high

what are the disadvantages of hydroelectric power?

* extra supply when needed

what does pumped storage give?

* spare night time electricity is used to pump water up to a higher reservoir
* released quickly when high demands
* spare electricity used to transfer energy back to water GPE so more electricity can be generated

how does pumped storage work?