P2-energy transfer by heating Flashcards
define conduction
A conductor of heat is when a material allows heat to pass through it easily
define insulation
An insulator does not allow heat to pass through it easily
explain the process of
When a bunsen burner is placed at one end of the metal rod, the thermal energy transferred to the rod becomes kinetic energy, causing the nearest particles to vibrate. As the particles in a metal are arranged in a regular, compact pattern these particles collide into those near them causing them to vibrate and this occurs down the rod, allowing the thermal energy to spread through the rod, and this is conduction.
define fluids
Fluids = liquids and gases
define convection
Convection = the transfer of heat through fluids
what is the electromagnetic spectrum
Electromagnetic waves is a spectrum where every type of radiation on this spectrum comes from the Sun
which objects emit infrared radiation
All objects emit (give out) infrared radiation
how does temperature affect infrared radiation
The higher the temperature of an object the more infrared radiation it emits in a given time
what does colour black have in relation with heat/radiation
A black body emits and absorbs radiation the most effectively
which absorbs and emits heat faster, light and shiny or dark and matte
A light shiny outer surface emits radiation a lot less than a dark matt surface
what does temperature of earth depend on
The temperature of the Earth, it depends on factors such as the rate of that light and radiation from the Sun are:
1. reflected back into space or absorbed by the Earth’s atmosphere or surface
2. emitted from the Earth’s surface and atmosphere into space
what does specific heat capacity mean
Specific Heat Capacity = the energy needed to raise the temperature of 1kg of a substance by 1degree celsius
What is the difference between thermal energy and temperature?
thermal energy is heat and temperature is a measure of heat
How can we reduce heating bills(5 points)
1)Double-glazed windows - the thicker the glass, the lower the thermal conductivity (how easily it lets through). Between two panes of glass, there is a vacuum, which prevents the convection of heat energy
2) Loft insulation - fibreglass reduces rate of energy transfer through the roof. Air in this space allows heat energy to escape via conduction. The more layers of insulation, the thicker the insulation will be
3) Cavity wall insulation - reduces rate of thermal energy through outer walls of the house. Insulation is pumped into the cavity (space between two brick walls)
4) Aluminium foil between radiator panel and wall reflects the radiation away from wall and so reduces transfer of thermal energy via radiation
5) If external walls have thicker bricks and lower thermal conductivity, dissipation of thermal energy will be lower, so less bills
