Heat Flashcards
(32 cards)
Heat
Form of energy
The unit of energy is the
Joule(J)
Solids, liquids and gas expand
When heated
Solids, liquids and gas contract
When cooled
Bimetallic Strip
The different metals will expand and contract at different rates due to their different molecular properties
Conduction
Heat travels from particle to particle along a substance, normally a solid
Convection
Heat travels through a fluid (liquid or a gas) when the particles move and carry heat
Radiation
Heat travels from a hot object without the need for medium, does not need a solid, liquid or gas to go through a vacuum
Conductor
Something that allows energy e.g. heat to flow through it. E.g. metal is a good conductor
Insulators
Materials that are poor conductors of heat
Heat can travels in 3 different methods
Conduction, convection and radiation
When heat changes a liquid to a gas with no temperature change
We call it latent heat of vaporisation
When heat changes a solid to a liquid with no temperature change
We call it latent heat of fusion
When heat causes a change in state and not a change in temperature
We call it latent heat
Temperature is a measure of the
hotness of a body and the unit is the degree Celsius (C).
Increasing pressure raises the boiling point of water
above 100°C
Reducing pressure lowers the boiling point of water
below 100°C.
Below 4°C water behaves
oppositely to other liquids.
Above 4°C water behaves
like other liquids.
Radiation
Radiation is the transfer of heat from a hot object without the need of a medium
The sun transfers its energy by radiation
Temperature
A measure how hot an object is
Temperature is measured
By a thermometer
We deal with 2 types of thermometer
Mercury thermometer and alcohol thermometer
The liquid in the thermometer will
Expand and rise when heated and will contract and fall when cooled
