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21 Cards in this Set
- Front
- Back
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What is heat and what is it measured in? |
Heat is a measure of how much energy something has. It is measured in joules (J) |
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What is temperature and what is it measured in? |
Temperature is a measure of how hot something. It is measured in degrees Celsius (°C) or degrees Fahrenheit (°F) or kelvin (K). |
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What is specific heat capacity? |
Specific Heat Capacity is the amount of energy required to increase the temperature of 1kg of a substance by 1°C. |
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What is specific latent heat? |
Specific Latent Heat is the amount of energy required to change the state of a substance without changing the temperature. |
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What is the equation for Specific Heat Capacity (SHC)? |
Energy= mass X SHC X Temperature Change E= m X SHC X TC |
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What is the equation for Specific Latent Heat (SLH)? |
Energy= mass X Specific Latent Heat E= m X SLH |
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What happens to the temperature when a substance is changing state and why? |
The temperature stays the same because the energy is being used to break the bonds so it can change state. |
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What is heat transfer through solid objects called? |
Conduction |
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What is heat transfer through fluids? |
Convection |
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What is heat transfer through a vacuum called? |
Radiation |
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How does conduction work? |
The particles gain more kinetic energy and vibrate faster as the temperature increases. They then bump into each other, transferring energy. |
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How does conduction work? (metal) |
In a metal, the electrons can leave their atoms and move about in the metal as free electrons. The parts of the metal atoms left behind are now charged metal ions. The ions are packed closely together and they vibrate continually. The hotter the metal, the more kinetic energy these vibrations have. This kinetic energy is transferred from hot parts of the metal to cooler parts by the free electrons. These move through the structure of the metal, colliding with ions as they go. |
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How does convection work? |
The liquid or gas in hot areas is less dense than the liquid or gas in cold areas, so it rises into the cold areas. The denser cold liquid or gas falls into the warm areas. In this way, convection currents that transfer heat from place to place are set up. |
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What is a thermogram? |
Thermal imaging cameras can detect infrared radiation - the type of radiation emitted by all objects. The images they produce are called thermograms. The images show different temperatures through different colours. |
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Name at least 4 ways to reduce heat loss from a house |
-Loft Insulation - Hot Water Tank and Jacket -Cavity Walls & Insulation -Draught-proofing - Double Glazing - Thick Curtains |
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What is the equation for payback time? |
intial cost ÷ annual saving |
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What are the waves in the electromagnetic spectrum in order? |
Radio waves Microwaves Infrared Visible Light Ultraviolet (UV) X Ray Gamma Ray |
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What is the equation for wave speed? |
Speed = Wavelength X Frequency S= W X F |
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What is the equation for efficiency? |
(Useful Energy out ÷ Total Energy In) X 100 |
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What is Total Internal Reflection (TIR)? |
Beyond a certain angle, called the critical angle, all the waves reflect back into the glass. We say that they are totally internally reflected.If the angle of incidence is greater than the critical angle, TIR occurs. |
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What is multiplexing? |
This is where several digital signals are interleaved or carried together without being mixed. The signals can go through a multiplexer and be carried altogether. They can then be separated back out into the different signals. |
