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What is the effect of increasing the temperature difference (ΔT) across a material?
Increases the rate of heat transfer through the material, as described by Fourier's Law.
What is the effect of increasing the thickness (L) of a material?
Decreases the rate of heat transfer through the material, as described by Fourier's Law.
What is the effect of using a material with high thermal conductivity for a cooking pot?
The pot will heat up quickly and distribute heat evenly, cooking the food faster.
What is the effect of using a material with low thermal conductivity for insulation?
The insulation will resist heat transfer, keeping the inside of the insulated space warmer in winter and cooler in summer.
What is the effect of metallic bonding on thermal conductivity?
The 'sea of electrons' in metallic bonds allows electrons to move freely, carrying thermal energy and resulting in high thermal conductivity.
What is thermal conductivity?
A material property indicating how efficiently it conducts heat. High k = good conductor, low k = good insulator.
Define Fourier's Law of Conduction.
Fourier's Law describes heat conduction through a solid material, stating that heat flow is proportional to the temperature gradient and cross-sectional area, and inversely proportional to the thickness.
What does a high thermal conductivity (k) value indicate?
A high k value indicates that the material is a good conductor of heat, allowing heat to move through it quickly.
What does a low thermal conductivity (k) value indicate?
A low k value indicates that the material is a poor conductor of heat (a good insulator), resisting heat transfer.
What are the units for thermal conductivity?
Watts per meter per kelvin (W/m·K).
What is the difference between heat transfer in metals vs. non-metals?
Metals: High thermal conductivity due to freely moving valence electrons. Non-metals: Lower thermal conductivity due to lack of free electrons.
Compare the thermal conductivity of copper and aluminum.
Copper: Higher thermal conductivity, more efficient heat conduction. Aluminum: Lower thermal conductivity compared to copper.
Compare the feeling of touching metal vs. wood on a cold day.
Metal: Feels colder because it rapidly draws heat away from your hand. Wood: Doesn't draw heat away as quickly, so doesn't feel as cold.
Compare the feeling of touching metal vs. wood on a hot day.
Metal: feels hotter because it rapidly transfer heat to your hand. Wood: Doesn't transfer heat as quickly, so doesn't feel as hot.
Compare thermal conductivity of good conductors vs good insulators?
Good Conductors: High thermal conductivity, allows heat to move through it quickly. Good Insulators: Low thermal conductivity, resists heat transfer.