Effects of Heat Flashcards
- a state of matter characterized by elevation of temperature
- perceived as the opposite to cold
heat
Sources of heat generation
- Chemical heat production
- Mechanical heat production
- Electromagnetic heat production
- Electrical heat production
- Heat conduction
heat produced as by-product of metabolism. This can be a result of exercise (walking or running)
Chemical heat production
accomplished through friction e.g., rubbing hands or soles of feet together.
Mechanical heat production
accomplished through absorption and conversion of various diathermies and
radiant energies
Electromagnetic heat production
machine that produces a certain amount of electromagnetic radiation→producing
heat
Diathermies
o when ions and molecules in a system is stimulated, the particles are accelerated,
and random kinetic energy is produced which gives rise to heat production.
o This can be seen when an electric current is passed through a conductor, the conductor becomes hot
after some time and produces heat.
Electrical heat production
heat transfer
Heat conduction
Different modes of heat transmission:
- Conduction
- Convection
- Conversion
- Radiation
- Evaporation
heat transfer from a warmer object to a cooler object through direct molecular interaction
of objects in physical contact. Ex: frying pan and food
Conduction
heat transfer by movement of air or fluid from a warmer area to a cooler area. Ex: Heater
(used during winter)
Convection
heat is transfer by converting or changing one form of energy to another form of energy. Ex: Electromagnetic radiation into thermal energy.
Conversion
transfer of heat from a radiant energy without any intervening medium. Ex: Oven, microwave
Radiation
transfer of heat through steam. Ex: Spa
Evaporation
Types of heating
Vigorous heating
Mild heating
Wet/moist heating
Dry heating