Thermodynamics Flashcards
what are the four laws of thermodynamics
- energy can neither be created nor destroyed
- the entropy of a closed system can only increase
- Entropy approached zeros as the temperature
approaches zero - if two systems are equal in temperature with a third system, the two initial systems are in thermal equilibrium. (Transitive property exists)
what are some non-heat engines
electric motor
clockwork motor
fuel cells
electric kettle
why are perpetual motion motors impossible to work
because they violate the 1st & 2nd law of thermodynamics
what is entropy
chaos
what does heat/energy want to do
spread out (expand)
what is the equation for Carnot efficiency
n= (Th-Tc)/(Th)
what are the 3 heat engines
Stirling engine
Steam engine
Thermocouple
the ABSOLUTE temperature of a system…
does not matter
having a larger difference of temperature
Carnot efficiency increases
what was the difference between Watt’s and Newcomen’s steam engine
Watt’s Steam Engine was 4x as effective as Newcomen’s
Watt =
1 Joule/second
1 horsepower =
33,000 foot-pounds per minute
how much joules would take to raise you to the top of Grouse Mountain
1 Mega joule
one kilowatt/hour (Kw/h) is how many joules
3.6MJ
what is exergy
available energy
