2nd Law of Thermodynamics

This was the first experiment of the day where we created a system that when heated it increased pressure.

this is the graph representing the first experiment. We see that volume decreased when the pressure increase, but when a hit a certain point pressure increased and volume increased. This happens because the system is experiencing different thermodynamic processes.

Here we discuss the different thermodynamic processes. Here are some definitions: 

Adiabatic process: No heat transfer into or out of a system (Q=0); 

Isochoric process: constant volume (W=0);

 Isobaric process: constant pressure [W=p(V_2- V_1)];

Isothermal: Constant Temp  

Here are of the graphs of the thermodynamic processes. We found that Adiabetic process has a rapid change in volume and Isothermic has a slow change in volume. 

Here we have our next experiment, where we made a prediction of what would happen when we heated a rubber band, then executed the actual experiment. Our prediction was correct and we found that the rubber band did shrink when we heated it. A rubber band is a polymer, which when heated will shrink. 

This is where we created our mass lifting engine cycle, and discussed how the rubber does work. We need heat to create work, which gives us the equation: W=Q_H- Q_C this is true when internal energy is zero. 

We also have, E internal = Q- W.

This is where we discussed efficiency and derived the formula for it, which helped us gain understand of how it is applied to thermodynamics.

This is where we theoretically analyzed a heat engine cycle. We were given different pressure vs. volume points, we then calculated internal energy by first finding Q_c, Q_H and W, which is pictured below. 

here we have a chart of our ending results. At the points where volume is constant work is equal to zero.

For the last experiment we were given volume in cc and pressure and we were asked to calculate work and Q of the system. To finalize the experiment we were asked to calculate the net work.