physics final

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physics final
2012-12-11 22:38:18
physics final

physics final
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  1. 1st law of thermodynamics
    the internal energy of a system can be increased by either adding heat or doing work on the system
  2. ideal gas law
    • an ideal gas is a gas for which the forces between atoms are small enough to be ignored. 
    • (Pressure x Volume)= (#gas atoms x Boltzman's constant x absolute temperature)

  3. convection
    heat is transferred by the motion of a fluid
  4. radiation
    heat is transferred by electromagnetic waves
  5. heat engine
    • gasoline engine.  not all heat is used when burning
    • Thermal engery- burning gas.  
    • some energy converted to work
    • some heat is released into enviorment 
  6. efficiency
    net work done by the engy by the amount of heat used to do this work.  E= W/Qh
  7. e= W/Qh
    • efficiency.
    • convert to kelvins
  8. carnot engine
    • ideal efficiency
    • Ec= (Th-Tc)/Th
  9. second law of thermodynamics
    some energy is always lost 
  10. heat pump
    refrigerator- cold air becoming warmer
  11. e=F/q
    • electric field= force vector/ charge
    • units are N/C
  12. PE=qEd
    electrostatic potential energy
  13. V= PE/q
    electric potential
  14. V= Ed
    relationship between electric field and potential
  15. I= q/T
    • electric current
    • I is electric current, q is charge, and T is time
    • unit =ampere= C/s
  16. Ohms law
    I= V/R

    unit= Omega
  17. electrical motive force
    • E=I/R
    • unit = voltage
  18. P=IE
    Power supplied by the battery. 
  19. P=VI
    power dissipated by a resistor
  20. energy
    • power/time 
    • kilowatt kW