Q = nCPT, CP = CV + R = (7/2) R Q = (3)(7/2)R(100) = 8725 J Randomness Classical thermodynamics is deterministic Every time! But the real world is probabilistic
It is possible that you could add heat to a system and the temperature could go down The universe only seems deterministic because the number of molecules is so large that the chance of an improbable event happening is absurdly low
Random Gas Motions Gas Motions Why dont gasses diffuse more rapidly? They do not travel in a straight line
Energy and information is quickly transmitted through the gas Mean Free Path The average distance between collisions: = 1 /[2 d2 (N/V)] Where: V is the volume
Millions of collisions per second! Maxwells Distribution Speed Distribution Maxwells distribution is not symmetrical
This means there are several ways to characterize a average speed Most probable speed, vp vp = (2RT/M) Average speed, vavg
vavg = (8RT/M) root-mean-squared speed, vrms vrms = (3RT/M) rms speed reflects the way the molecules produce pressure and carry energy Titan
Why does it have an atmosphere? What type of gas might the atmosphere be made of? Planetary Atmospheres
Why do some planets have atmospheres and others do not? So equating escape velocity to thermal velocity should define conditions for atmosphere retention
Escape velocity needs to be about 10 times large than rms velocity in order to keep an atmosphere for a long time: (2GMplanet/Rplanet) > (300kT/mmolecule) The Arrow of Time Why?
The smashing plate is an example of an irreversible process, one that only happens in one direction Examples: Entropy They all progress towards more
randomness For an irreversible process, entropy always increases Determining Entropy In any thermodynamic process that proceeds from an initial to a final point, the change in entropy
depends on the heat and temperature, specifically: Isothermal Expansion A cylinder of gas rests on a thermal reservoir with a piston on top Heat also flows into the system from the reservoir
The temperature is constant so S=Q/T Closed Systems Consider a closed system The heat lost by the reservoir was gained by the gas so there is no net heat loss or gain
For a reversible process in a closed system the entropy is constant Second Law of Thermodynamics No real process is truly reversible (due to friction, turbulence etc.), so we can say:
No "Spiky" Profile allowed. Entry Level overall assessment time: Minimum - 1hr 30mins Maximum - 2hrs . GLH set at 55 hours. English - Key content changes for Entry Levels. Content Changes (English) Phonics and spelling tests are new to...
Flatworms have a solid body and incomplete or absent gut. There are three classes of flatworms. planarians flukes tapeworms The intermediate host in the tapeworm life cycle is the flea. Mollusks are diverse animals. Mollusks and other bilateral animals have...
Members enjoy reduced costs due to greater bargaining power and marketplace strength associated with the larger group. Florida's Natural Growers is a cooperative of citrus growers who own their own groves in Florida. As a group, they invested in machinery...
Directions: First, students will need to reflect on the culture of the town of Maycomb. We have been exploring this topic throughout our work on the novel. Reviewing your completed journal entries, town map project, interview worksheets, and study guides...