Slides in this set
· Infrared radiation can also be called heat radiation. Infrared radiation is energy
transfer by electromagnetic waves. Infrared radiation does not need particles to
move so can pass through everything.
· The Sun emits all types of electromagnetic radiation but the Earth's atmosphere
blocks most of the harmful radiation out, but it doesn't block out infrared radiation.
· All objects emit infrared radiation.
· Hot objects: emit more infra red than it absorbs.
· Cold objects: absorb more infra red than it emits.
· The smaller the volume/mass the faster the temperature change.
· The larger the surface area the faster the rate of heat transfer.
· The larger the temperature difference to the surroundings the faster the rate of heat
1.2 SURFACES AND
· Dark matt colours absorb and emit much more radiation thank light shiny colours.
· Light shiny colours will reflect more radiation than dark matt colours.
· That is why we use:
· Matt black solar hot water panels that easily absorbs a lot of heat and the shiny
inner surface to keep absorbed heat in.
· Silver survival blankets that help stop their body heat radiating away, which could
save someone's life.…read more
1.3 STATES OF MATTER
· Flow, shape, volume and density the properties used to describe each state of matter.
· 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
· A substance can change from one state to another. We can make these changes by heating or
cooling the substance.
· When water in a kettle boils, the water turns to steam. Steam is water vapour in its gaseous state.
· When solid carbon dioxide or `dry ice' warms up, the solid turns into gas directly.
· When steam touches a cold surface, the steam condenses and turns to water.…read more
· Conduction of heat is when vibrating particles collide and pass on their extra
kinetic energy. It occurs mainly in solids.
· Metals are good conductors of heat because they have electrons which can move
freely. Non metals are poor conductors because they do not have free electrons.
· Poor conductors of heat like wood and plastic are called insulators.
· Particles are involved and needed for conduction.…read more