Heat Transfer: Conduction and Convection

Definition of Heat

• Heat is a form of energy that is transferred from one body to another due to a difference in temperature.
• It is a measure of the kinetic energy of particles in a substance.

Types of Heat Transfer

• Conduction: transfer of heat between objects in physical contact.
  • Occurs in solids, where atoms vibrate and collide, transferring energy.
• Convection: transfer of heat through the movement of fluids.
  • Occurs in liquids and gases, where heated particles move away from the source, carrying energy with them.
• Radiation: transfer of heat through electromagnetic waves.
  • Occurs over long distances, without a medium (e.g., sunlight).

Heat Transfer Mechanisms

• Heat Capacity: the amount of heat energy required to change the temperature of a substance by 1°C.
  • Specific heat capacity: the amount of heat energy required to change the temperature of 1 gram of a substance by 1°C.
• Latent Heat: the energy required to change the state of a substance (e.g., melting, boiling).
  • Latent heat of fusion: energy required to change from solid to liquid.
  • Latent heat of vaporization: energy required to change from liquid to gas.

Heat Measurement

• Temperature: a measure of the average kinetic energy of particles in a substance.
  • Measured in Celsius (°C), Fahrenheit (°F), or Kelvin (K).
• Thermometer: a device used to measure temperature.
  • Types: digital, mercury, thermocouple.

Heat Applications

• Heating and Cooling Systems: used to control temperature in buildings, vehicles, and electronic devices.
• Cooking and Food Preparation: heat is used to cook, bake, and preserve food.
• Energy Generation: heat is used to generate electricity in power plants.

Definition of Heat

• Heat is a form of energy transferred between objects due to a temperature difference.
• It is a measure of the kinetic energy of particles in a substance.

Types of Heat Transfer

• Conduction: occurs in solids, where atoms vibrate and collide, transferring energy between objects in physical contact.
• Convection: occurs in liquids and gases, where heated particles move away from the source, carrying energy with them.
• Radiation: occurs over long distances, without a medium, transferring energy through electromagnetic waves.

Heat Transfer Mechanisms

• Heat Capacity: the amount of heat energy required to change the temperature of a substance by 1°C.
• Specific Heat Capacity: the amount of heat energy required to change the temperature of 1 gram of a substance by 1°C.
• Latent Heat: the energy required to change the state of a substance (e.g., melting, boiling).
• Latent Heat of Fusion: the energy required to change from solid to liquid.
• Latent Heat of Vaporization: the energy required to change from liquid to gas.

Heat Measurement

• Temperature: a measure of the average kinetic energy of particles in a substance.
• Thermometer: a device used to measure temperature.
• Temperature Units: Celsius (°C), Fahrenheit (°F), or Kelvin (K).

Heat Applications

• Heating and Cooling Systems: control temperature in buildings, vehicles, and electronic devices.
• Cooking and Food Preparation: heat is used to cook, bake, and preserve food.
• Energy Generation: heat is used to generate electricity in power plants.