## Entropy and the Second Law

PIRA classification 4F

 Grayed Demos are either not available or haven't been built yet.

# 4F10. Entropy

 PIRA # Demonstration Name Subsets Abstract 4F10.00 Entropy 4F10.10 time reversal 4F10.10 time reversal An ink column in glycerine between two concentric rotating cylinders appears to mix and unmix. 4F10.10 unmixing demonstration The area between coaxial cylinders is filled with a Newtonian fluid and a suitable tracer. When the inner cylinder is rotated, the tracer appears to be mixed but is distributed in a fine one armed spiral sheet. Reversing the direction of inner cylinder rotation will cause the original tracer pattern to reappear. 4F10.10 order and disorder Ink seems to be mixed in glycerine but can be unmixed. 4F10.10 un-mixing Glycerine between two concentric cylinders. Animation. 4F10.11 capacitor charging entropy change A simple demonstration-experiment that measures the difference in change of temperature due to charging a capacitor in many steps or one step. 4F10.20 balls in a pan 4F10.20 balls in a pan Three red balls and three yellow balls are mixed in a pan. 4F10.25 communication time and entropy Demonstrate entropy with the time it takes a student to communicate the structure of ordered and disordered playing cards, and a salt crystal model, etc. 4F10.30 Hilsh tube 4F10.30 Hilsh tube 4F10.30 Hilsch tube The Hilsch tube is a sort of double vortex that separates hot and cold air. 4F10.40 dust explosion 4F10.40 dust explosion 4F10.40 dust explosions Disperse dust in a can with a squeeze bulb and use a spark to set off the explosion. 4F10.40 dust explosion Blow a teaspoon of lycopodium powder into a covered can that contains a lighted candle inside. 4F10.40 dust explosion Blow lycopodium powder into a can containing a candle. 4F10.45 gas explosion Fill a can that has a hole on top and bottom with illuminating gas and light the top hole. The flame burns low and then the can explodes.

# 4F30. Heat Cycles

 PIRA # Demonstration Name Subsets Abstract 4F30.00 Heat Cycles 4F30.01 Hero's engine see 3C55.35 4F30.01 drinking bird see 4E31.20 4F30.10 Stirling engine pira200 Show both a working Stirling engine and a cutaway model. 4F30.10 Stirling hot air engine A Stirling hot air engine. 4F30.10 hot air engine Pictures and diagram of a hot air engine that can be run as a hot or cold engine or driven both ways. 4F30.10 Stirling engine Shows the standard Stirling engine, includes good animation. 4F30.11 the stirling engine explained An explanation of how the Stirling engine works. Good diagrams. (We had to machine off the top half of one to convince the faculty) 4F30.20 steam engine 4F30.20 steam engine A small steam engine runs from a small alcohol lamp. 4F30.20 steam engine A small steam engine powers a small electric generator. 4F30.22 room temperature steam engine Place an inflated balloon on the end of a capped copper tube and immerse the tube in liquid N2. Place a weight the collapsed balloon and it will rise when the balloon warms up. 4F30.25 Liquid nitrogen engine Convert a small steam engine to run on liquid nitrogen. 4F30.25 liquid air steam engine Run a model steam engine by connecting a test tube of liquid air to the boiler. 4F30.30 Hilsh tube 4F30.30 Hilsh tube 4F30.31 model steam engine Picture of a model steam engine. 4F30.35 compressed air engine The parts of a steam engine that runs on compressed air. 4F30.40 refrigerator 4F30.50 engine models Models of different engines are shown. 4F30.52 model gasoline engine A picture of a model gasoline engine. 4F30.55 air/ocean uniform temperature engine An experimental engine that shows that it is possible to extract heat from a nonhomogeneous uniform temperature reservoir. The humidity must be less than 100% as evaporative cooling is used. 4F30.56 ratchet and pawl model Use of a ratchet and pawl model to discuss the second law. Diagram, Construction details in appendix, p.1287. 4F30.60 Nitinol engine 4F30.60 Nitinol engine 4F30.60 Nitinol engine comments Comments on AJP 52(12),1144 taking issue with several points. 4F30.60 Nitinol engine Short thermodynamic discussion of the Nitinol engine. 4F30.70 rubber band engine 4F30.70 rubber band motor A wheel with rubber band spokes turns when heated locally with a spotlight. 4F30.70 rubber band motor The spokes of a bicycle wheel are replaced with rubber bands and a heat lamp is focused on one area causing the bands to contract at that point. Pictures. 4F30.71 rubber band motor thermodynamics An analysis of the thermodynamics of a simple rubber band heat engine. 4F30.76 optimizing the rubber-band engine An appropriate choice of dimensions maximizes the torque of an Archibald rubber-band heat engine. Plenty of analysis. 4F30.90 Buchner diagram extensions Comments extending the Buchner diagram to irreversible systems. 4F30.91 Bucher diagrams A new diagram of the Carnot cycle to replace the pipeline diagram. 4F30.95 Carnot cycle diagrams A set of thirty different Carnot cycle diagrams.

fw: SecondLaw (last edited 2018-07-18 19:29:34 by srnarf)