15 - Quantity of Heat and Heat Transfer

The heat energy needed to change the temperature of an object by 1 K (1 °C)

The heat energy needed to change the temperature of 1 kg of a substance by 1 K (1 °C)

The amount of heat energy needed to change the state of a substance
without a change in temperature

The amount of heat energy needed to change the state of 1 kg of a substance
without a change in temperature

The amount of heat energy needed to change 1 kg of a substance
from a solid to a liquid
without a change in temperature

The amount of heat energy needed to change 1 kg of a substance
from a liquid to a gas
without a change in temperature

*Learn Diagram*

Transfers energy from a cooler region to a warmer one. Work must be done to bring this about. It is used in refrigerators and in air conditioning systems in buildings and cars.

The circulating liquid has a high specific latent heat of vaporisation and a low boiling point

The transfer of heat energy through a substance
by the passing on of molecular vibration from molecule to molecule
with no overall motion of the substance

The U-value of a susbtance is the amount of heat energy per second passing through 1 m² of that substance when a temperature difference of 1 °C (1 K) is maintained between its ends

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*How well part of a building conducts heat
*Bad insulators (good conductors) have high U-value

the transfer of heat energy from one place to another by electromagnetic waves

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*Darker: more radiation
*Shiny: less radiation (I think)

The average amount of the Sun's energy falling per second
perpendicularly on 1 m² of the Earth's atmosphere.

Its value is 1.35 kW m⁻²

Solar Panels

Tubes to heat water p172 fig 15.12

the transfer of heat energy through a fluid
by using circulating currents of fluid.