Energy for the Home

Oliver Wood
Mind Map by , created almost 6 years ago

AS Level Physics (P1: Energy for the Home) Mind Map on Energy for the Home, created by Oliver Wood on 11/19/2013.

Oliver Wood
Created by Oliver Wood almost 6 years ago
P1 - Heat Radiation, Kinetic Theory, Conduction and Convection
The Big Bang
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P1.5 The Use Of Waves For Communication
Religious Studies- Marriage and the family
Emma Samieh-Tucker
Introduction to the Atom
Sarah Egan
OCR Gateway Physics - P1
Rattan Bhorjee
P1 - Energy for the Home
Rattan Bhorjee
Physics P1
Physics P1
P1.1 The Transfer Of Energy By Heating Processes
Energy for the Home
1 Energy
1.1 Energy flow
1.1.1 Hot body to cold body
1.1.2 Energy decreases as energy flows out
1.2 Measuring temperature
1.2.1 Specific Heat Capacty Amount of energy needed to raise 1kg by 1°C J/kg °C
1.2.2 Energy transfer by Specific Heat Capacity: Energy transferred = mass x spec. heat capacity x temp. change
1.3 Specific Latent Heat
1.3.1 Energy needed to melt/boil 1kg of a material Measured in (J/kg) When changing states, energy is transferred but temp. remains constant Energy is used to break intermolecular bonds instead Energy transfer = mass x specific latent heat E.g. Water SLH = 340,000
2 Insulation
2.1 Double glazing
2.1.1 Reduces heat lost by convection
2.1.2 two glass panels filled with vaccum OR gas E.g. argon
2.2 Loft insulation
2.2.1 Reduces heat lost by conduction and convection
2.2.2 Hot air in home rises
2.2.3 Stops energy transfer between ceiling to loft AND ceiling to roof
2.3 Cavity Wall
2.3.1 Reduces conduction and convection Air in foam insulates Air is trapped by foam
2.4 Insulation blocks
2.4.1 Shiny foil on either side Reflects sun's energy back during summer Home's energy is reflected inward during winter
3 Conduction, Convection, Radiation
3.1 Conduction
3.1.1 Kinetic energy between particles
3.2 Convection
3.2.1 Gas expands when heated Makes it less dense so rises Density in kg/m3 OR g/m3 Density = Mass/Volume
3.3 Radiation
3.3.1 Needs no medium
3.3.2 Travels through vacuum
4 Energy Efficiency
4.1 efficiency = useful energy output (x100%) / total energy input
4.2 Shown by Sankey diagrams
4.2.1 Source energy is lost to 'sink'
4.3 Different insulation types vary in cost and efficiency
4.3.1 Payback time = Cost of Insulation / Annual Saving
4.3.2 All things waste some energy
4.4 Efficient buildings lose little energy to surroundings
4.4.1 Designers and architects consider this
5 Waves
5.1 Wave Terms;
5.1.1 Amplitude = maximum displacement from rest position
5.1.2 Crest = Highest point
5.1.3 Trough = Lowest point
5.1.4 Wavelength = Distance between two successive points
5.2 Wave speed = Frequency x Wavelength
5.3 Measurements
5.3.1 Frequency: Hertz (Hz)
5.3.2 Wavelength: Metres (m)
5.3.3 Speed: Metres/second (m/s)
5.4 Types & Properties
5.4.1 Radio
5.4.2 Microwave
5.4.3 Infra-red
5.4.4 Visible
5.4.5 Ultra-violet
5.4.6 X-ray
5.4.7 Gamma
5.5 Changing Waves
5.5.1 Refraction Occurs as wave enters a denser medium Wave speed changes (Frequency stays same but wavelength changes)
5.5.2 Diffraction Wave spreads out after passing through gap 90° when wavelength = gap size Noticeable in telescopes and microscopes
5.6 Cooking and Communicating
5.6.1 Infrared doesn't penetrate food well
5.6.2 Microwaves penetrate 1cm Reflected by special glass
5.6.3 EM Spectrum Energy transfer depends on Wavelength Frequency High frequency (short wavelength) transfers more energy
5.6.4 Microwave lengths Between 1mm and 30cm Mobile phones = longer wavelengths Transfer less energy
5.6.5 Microwave communication Used over long distances Transmitter + receiver need line of sight E.g. top of high buildings Satellites are used Signal recieved from Earth Amplified Retransmitted to Earth Signal strength Little diffraction Strong weather and large water bodies scatter signals Curvature of earth Limits line of sight Transmitters must be high up/near Interference with equipment Bannings Hospitals Planes
6 Light and Lasers
6.1 Morse Code
6.1.1 Series of dots and dashes A digital signal
6.2 Signals
6.2.1 Can be sent by Electromagnetic Spectrum or electricity: Almost instantaneous Criticising each method Speed? Can it be seen? Can wires be cut? How far must it travel?
6.3 Laser Light
6.3.1 Single frequency (White light has many at once)
6.3.2 In phase (Syncronised) White light is mixed)
6.3.3 CDs Surface is pitted Pits = digital signal Laser shone on surface DIfferent reflections provide signal
6.4 Critical Angles
6.4.1 More dense --> Less dense °Refraction > °Incidence
6.4.2 When °Incidence makes °refraction = 90° That °incidence is 'critical angle' When °Incidence is GREATER than critical angle Total internal reflection occurs (TIR)
6.4.3 Use in communicatinons Fibre optics Telephone Computer Data travels at speed of light (200,000km/s in glass)
6.5 Endoscopy
6.5.1 Light sent down optical fibres Reflects off patient's insides Light is picked up by endoscope
7 Data Transmission
7.1 Infrared signals for electronics
7.2 LED pulses a digital IR signal
7.2.1 Start command
7.2.2 Instruction command
7.2.3 device code
7.2.4 Stop command
7.3 Analogue/Digital switch
7.3.1 2009 - 2015
7.3.2 Greater program choice
7.3.3 Interaction
7.3.4 Subtitles
7.4 Digital Signal advantages
7.4.1 No damaging interference from other waves
7.4.2 Multiplexing Multiple waves combined and sent together
8 Wireless Signals
8.1 Less atmospheric refraction at high frequencies
8.2 Digital Audio Broacasting (DAB)
8.2.1 Greater range
8.2.2 Eliminates interference
8.3 Radio reflection
8.3.1 Reflected by the Ionosphere
8.3.2 Signal can pass around Earth
8.4 Microwaves pass through Ionosphere
8.4.1 Comms. satellites Geostationary orbit
8.5 Problems
8.5.1 Radiowaves diffract
8.5.2 Satellites require focused signals Beams split (diverge)
9 Stable Earth
9.1 Earthquakes
9.2 Ozone Depletion
9.2.1 Found in Stratosphere 10km - 30km up
9.2.2 Filters UV
9.2.3 Chlouroflourocarbons (CFCs) Depletion highest at the poles
9.2.4 Monitored using IR satellites