P2. Specific Heat Capacity Flashcards
(24 cards)
What does the term ‘thermal’ mean?
Thermal - a term relating to heat/heat energy.
What does the term ‘conduct’ mean?
Conduct - means to lead, guide or transmit.
What does ‘thermal conductivity’ refer to?
Thermal conductivity of a material refers to the rate at which it transfers heat energy.
What is insulation?
Insulation means to reduce the amount of energy transfer across a material. Therefore, thermal insulation is to reduce the rate of heat energy transfer.
Identify materials that would make good thermal insulators.
Wood, Brick, air.
What do these materials have in common?
They are all conductors, therefore insulators.
What factors affect the rate of heat transfer across a material?
The rate of energy transfer across a material depends on:
• the temperature difference across the material.
• The thickness of the material.
• The thermal conductivity of the material.
Name a few materials that make good conductors.
Copper, Aluminium, Silver, Iron etc..
Metals are commonly the best conductors.
What type of material should the handle to a pan be made of?
A thermal insulator, a material which is a poor thermal conductor.
What does it mean if the/a material is better at conducting heat out of a house?
It means that it has a higher thermal conductivity.
What is Heat?
Heat is the amount of energy stored in an object or substance.
Heat can also refer to the amount of energy transferred from one object to another.
What is Temperature?
Temperature is a measure of how hot or cold something is due to that energy.
What is a perfect black body?
A perfect black body is an object that absorbs all of the radiation that hits it.
What does a black body do with radiation?
A black body does not reflect or transmit any radiation.
What is the relationship between absorption and emission in a black body?
Since a good absorber is also a good emitter, a perfect black body would be the best possible emitter.
What is radiation emitted by a perfect black body called?
Radiation emitted by a perfect black body is called ‘black body radiation’.
What happens to a body as it absorbs infrared radiation?
As the body absorbs infrared radiation at greater rate than it emits it the body increases in temperature
What happens to a body as it emits infrared radiation?
As the body emits infrared radiation at a greater rate than it absorbs it the body decreases in temperature
Explain what happens to bodies temperature that absorbs infrared radiation at the same rate
as it emits it?
A body that absorbs infrared radiation at the same rate as it emits it will remain at a constant temperature
What is infrared radiation?
It is a type of electromagnetic wave which transfers heat energy
Identify 3 different sources of infrared radiation.
The sun, a human body, hot water(any named body)
Explain what makes a ‘perfect black body’ so interesting in terms of infrared radiation.
A perfect black body absorbs all infrared radiation that falls onto it, without transmitting or reflecting any of it. The best possible absorber or emitter of infrared.
Explain why a filament bulb emits more yellow-white light as it gets hotter.
At lower temperatures the filament emits longer wavelengths (red), as the temperature increases it emits wavelengths as shorter wavelengths(yellow).
