energy transfer by heating
- Created by: meganbeaney
- Created on: 13-05-15 16:59
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- energy transfer by heating
- Infrared radiation
- infrared radiation is energy transfer by electromagnetic waves
- all objects emit infrared radiation
- the hotter an object is the more infrared radiation it emits in a given time
- evaporation and condensation
- evaporation is when a liquid turns to gas
- condensation is when a gas turns into a liquid
- cooling by evaporation of a liquid is due to the faster moving molecules escaping from the liquid
- evaporation can be increased by increasing the surface area of a liquid, increasing the temperature or by creating a draught of air
- states of matter
- flow, shape, volume and density are the properties used to describe each state
- the particles in a solid are held next to each other in fixed positions
- the particles in a liquid move about at random and are in contact with each other
- the particles in a gas move about randomly and are much further apart than particles in a solid or liquid
- conduction
- metals are the best conductors of energy
- materials such as wool and fiberglass are the best insulators
- conduction of energy in a metal is due to free electrons transferring energy inside the metal
- Untitled
- convection
- convection is the circulation of a fluid caused by heating it
- convection takes place only in liquids and gasses
- heating a liquid or gas makes it less dense so it rises
- energy transfer by design
- the rate of energy transferred to an object depends on : size , material, temperature
- specific heat capacity
- the greater the mass of an object the more slowly its temperature increases when it is heated
- the rate of the temperature change of a substance when it is heated depends on : energy supplied to it, its mass , the shc
- storage heaters use off peak electricity to store energy in special bricks
- heating and insulating buildings
- energy transfer from our homes can be reduced by fitting loft insulation, cavities, double glazing and aluminium behind radiators
- uvalues tells us how much energy per second passes through different materials
- solar heating panels do not use fuel to heat water but they are expensive to buy and install
- surfaces and radiation
- Dark matt surfaces absorb more infrared radiation that light shiny surfaces
- dark matt surfaces emit more infrared radiation that light shiny surfaces
- light shiny surfaces reflect more infrared radiation than dark matt surfaces
- Infrared radiation
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