option b - thermodynamics year 13 sl physics. thermodynamics system – environment of activity...
DESCRIPTION
Work on a System Work done on a system or energy transferred to the system because of temperature differences result in the internal energy of that system increasing No change in state – Increase in Kinetic Energy Change in State – Increase in potential energyTRANSCRIPT
Option B - Thermodynamics
Year 13 SL Physics
Thermodynamics
• System – Environment of activity• Surroundings – Factors impacting the system• Boundary (wall) – System barriers
Work on a System
• Work done on a system or energy transferred to the system because of temperature differences result in the internal energy of that system increasing
• No change in state– Increase in Kinetic Energy
• Change in State– Increase in potential energy
Internal Energy
• Total Internal Energy of a System = – Total Potential Energy + Random Kinetic Energy of
all particles
Ideal Gas
• Internal Energy is all kinetic
0th Law of Thermodynamics
1st Law of Thermodynamics
• Changes to Internal Energy– Doing work on the system• Allowing the system to do work on the surroundings
– Transferring energy to or from the system as a result of a difference in temperature
Q = ΔU + W
Types of Work Done
• Isobaric Changes– Constant Pressure
• Isothermal Changes– Constant Temperature
• Adiabatic Changes– Constant Energy
• Isovolumetric Changes– Constant Volume
Isobaric Changes
• Pressure is constant• Q = ΔU + pΔV• W is positive = expands• W is negative = compressed
Isobaric Changes
Isothermal Changes
• Temperature is constant– So internal energy of the system remains constant
• Q = W– Where W = pΔV
Isothermal Change
Adiabatic Changes
• Constant Energy– No energy is
transferred• Usually contains
a well insulated barrier between the system and surroundings
Isovolumetric Changes
• Constant volume– So no work done
• Q = ΔU
2nd Law of Thermodynamics
• It is impossible to transfer energy from a body at a lower temperature to one at higher temperature without doing work on the system
• It is impossible to extract energy from a hot reservoir and transfer this entirely into work.
• Law of Entropy
Entropy• All materials move towards
disorder
• ΔS = measurement of entropy
• ΔQ = energy absorbed by the system
• T = temperature in Kelvin
• We will do some examples and practice problems on Friday. But please learn these terms – That means you will need to study them Hubert