CSET 119: Heat Transfer and Thermodynamics

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CSET 119: Heat Transfer and Thermodynamics
2013-06-11 04:10:14

Science CSET
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  1. Know the principle of conversion of energy and apply it to energy transfers
    • the overall energy in a given system is interchangeable - heat energy can flow from one object to another 
    • the energy within the universe is constant - energy can be transferred and transformed from one form of energy to another, but it can neither be created nor destroyed 

    heat transfer - as the heat transfers to the molecules which are in a state of lower kinetic energy or potential energy the surrounding molecules will tend to increase in kinetic energy and decrease in potential energy, energy flows from one object to another
  2. Discuss how the transfer of energy as heat is related to changes in temperature
    • heat can be transferred from objects with a higher thermal energy to surrounding objects with a lower thermal energy
    • this transfer of heat can increase the overall kinetic energy of the surrounding system, causing a difference in temperature
  3. Diagram the direction of heat flow in a system
  4. Describe the methods of heat transfer by conduction, convection, and radiation, and provide examples for each
    • conduction - transfer of thermal energy through matter from one atom or molecules to another 
    • ex - a spoon in a cup of hot tea becomes warmer because the heat from the hot liquid is conducted along the spoon from metal atom to metal atom by electrons in the metal 

    • convection - the transfer of thermal energy in a fluid is due to the motion of the atoms or molecules from place to place, this results in the actual motion of the fluid
    • can also take places in some solid matter 
    • ex- responsible for making pasta rise and fall in a pot of heated water, the warmer portions of water are less dense and rise to higher levels, at the same time the cooler portions of the water travel to the lower portions because they are denser 

    • radiation - transfer of thermal energy caused by electromagnetic waves that emitted from objects 
    • ex - sunlight, x-rays, infrared rays
  5. Explain how chemical energy in fuel is transformed to heat
    • chemical energy is a type of stored potential energy contained in the specific structural arrangement of atoms or molecules 
    • chemical energy of a chemical substance can be transformed to other forms of energy by specific chemical reactions 
    • when fuel is burned, the chemical energy is converted to heat energy, the majority of this type of energy is lost to the external environment
  6. Design and explain experiments to induce a physical change such as freezing, melting, or boiling
    heating or freezing water
  7. Distinguish between physical and chemical changes and provide examples of each
    • physical - there is a change only in the physical nature or appearance of a substance and there is not change in chemical composition
    • result in the same substance with a change only in the form or shape
    • new substances are not created 
    • ex - freezing of water 

    • chemical - there is change in the chemical composition of a substance 
    • result in the formation of new substances 
    • ex - burning of wood, chemical reactions in the chloroplasts of plant cells cause the formation of sugar