Heat and Thermodynamics

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Heat and Thermodynamics

• Rachel Sandman
• Kristen Schlotman
• Kiara Sierra
• Physics, period 6

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Temperature

• Temperature tells how hot or cold something is.
• Three scales Celsius, Fahrenheit, and Kelvin.

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Heat and Internal Energy

• Heat always flows from higher temperature
  substances to lower temperature substances.

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Measurement of Heat

• The units for heat are the calorie and the
  kilocalorie (1000 calories).

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Specific Heat Capacity

• Different substances have different capacities
  for storing internal energy.

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Thermal Expansion

• An increase in heat causes an expansion of the
  substance.
• An example is a thermostats bimetallic strip.

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Conduction

• Heat is transferred through objects by
  conduction.
• Metals are the best conductors.

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Insulation

• Insulators delay the transfer of heat.
• Liquids and gases in general are good insulators.

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Convection

• Through convection, heating occurs by currents in
  a fluid.

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Radiation

• The suns heat is transmitted through radiation.
• Energy transmitted by radiation is called radiant
  energy.

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Newtons Law of Cooling

• The rate of cooling of an object is approximately
  proportional to the temperature difference
  between the object and its surroundings.

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Phase Changes

• Evaporation (liquid to gas)
• Condensation (gas to liquid)
• Boiling (liquid to gas)
• Freezing (liquid to solid)

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First Law of Thermodynamics

• Whenever heat is added to a system, it transforms
  to an equal amount of some other form of energy.

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Second Law of Thermodynamics

• Heat will never of itself flow from a cold object
  to a hot object.

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Entropy

• Entropy is the measure of the amount of disorder.
• As disorder increases, entropy increases.