AP Physics Chp 15. Thermodynamics – study of the relationship of heat and work System vs Surroundings Diathermal walls – allow heat to flow through Adiabatic walls – do not allow heat to flow. Zeroth Law of Thermodynamics
What is the change in the internal energy if you supply 15 kJ to a 35 m3 sample of helium at 101150 Pa and it is allowed to expand to 52 m3?
One way to relate work for a system is to plot the P vs V graph and compare the area under the “curve”.
Why is it more than 9 m3 to 8 m3?
What would a graph for an isochoric process look like? Why does it show no work being done?
Any work done by the gas results in heat flowing out to the surroundings and vice versa.
When the gas does work the T decreases and the internal energy of the gas has decreased
If 2 moles of an ideal gas expands from 0.020 to 0.050 m3 at a pressure of 101300 Pa, how much work is done?
If the temperature is allowed/forced to remain constant how has the internal energy changed?
Carnot created a principle that says that a irreversible engine can not have a greater efficiency than a reversible one operating at the same temperatures.
If absolute zero could be maintained while depositing heat in then a 100% efficiency would be possible but it’s not.
If my truck operates at a running temperature of 94 oC and the outside air is only -5 oC, what is the maximum efficiency for the engine?
Why can’t you cool your house by running an air conditioner without having it exhaust outside?
If we set the hot coffee pot at 372K on the table at 297K and they exchange 4700 J of heat, how much has the entropy of the universe changed?