In order to achieve the goal in the experiment, which was to set the piece of cotton on fire by extremely fast compression, we needed a sealed tube that would release no air, and Q=0. The following video demonstrates the successful completion of the process which is adiabatic since there is no heat exchange.
Still image from video of actual combustion occurring.
We knew from the novel Fahrenheit 451 what the temperature required to ignite paper was, thanks to the title of the book and the recollection of the main events in the book. In order to get a greater understanding of what was occurring, we took measurements approximately with a digital measuring tool and took calculations based on those. We calculated the initial and final volume within the tube, and used these values to determine the actual temperature, which was over 1500 degrees Fahrenheit, well over 3 times the necessary temperature for ignition. The cotton can not be ignited again unless the syringe is opened and new air is allowed to enter, since the original air is blocked out by CO2 gas.
ActivPhysics Thermodynamics Section 8.4# 1-6
1. For question one we chose the first choice, positive upward sloping graph because we know that volume and temperature are directly proportional, and therefore in an Isobaric process they would increase with respect to each other.
2. For question two we chose the same type of graph, the first choice because there is a similar relationship between volume and pressure.
3. For question three we chose the third graph, because the relationship between pressure and volume is inversely proportional, so we need a graph that shows volume increasing as pressure decreases.
We used the ideal gas law to calculate the initial and final pressures.
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