23March2014

Nail Experiment

The nails represent the direction of the electric field and the flux is perpendicular to the area of the surface of the which is represent with the wire hanger. Using a ruler we measured the angle made with the surface and graphed how the angle changed with respect to the amount of nails covered by the surfaced. 

 The results of the graph are shown here and was fitted with a cosine wave. 

Active Physics

Here is a picture of one point charge inside of a shell. 

The field changes as a point charge is added and the magnitude changes.

19March2014

Electric Field Hockey

 A negative charge was used to attract the positive charged ball.

Here the ball was successfully placed in the goal. But it took more then one charge to guide it past the wall without a collision. 

It was very complicated trying to find a configuration that would allow the ball to hit the goal. But with two positive charges I was able to successfully make it in the goal. 

Active Physics 

This can was taken after analyzing questions 1 and 2

Here we are looking at a single point particle and it electrical field and the field lines tell us alot about the charge. 

We analyzed and saw that the larger the magnitude of the electric field the density of the field lines increases.

Used to analyze question 4

Used to analyze question 5

Used to analyze question 6.

 The Electric Field from an Extended Charge Distribution

The goal was to calculate the electrical field corresponding to a continuous charge distribution on a rod, and the point particle directly above it. The above calculations show the electrical force when the point particle is 5 cm above a rod overing over a 10cm rods center point.

17March2014

Electrostatic Forces

The picture of tape shown above shows the repulsion between the two pieces of tape. A charged is created in the piece of tape when they are pulled off. Depending on the way they were oriented they either repelled or attracted each other. 

Here is the qualitative understanding of what we did with the tape experiment.  

Like Charge Repulsion Experiment

Logger pro was used to determine the repulsion force verses the distance in the movie of a charged ball being pushed toward another like charge ball.  This graph show that the force of the electrical repulsion is inversely proportional to the square of the distance. 

 In this photo we are showing that Coulombs law accounts for the inverse relationship between the force and the distance we saw in the graph. 

12March2014

The Diesel Engine

The initial Diesel engine problem was given in class. We were expected to find the P, V, T, Q, W, dU, dS at every point and in-between each point. In addition we were expected to find the efficiency of the diesel cycle.

Here are the calculations for the P,V,T, dU, Q, and W. For each point and each process. 

Here are the calculations for the change in entropy of the system and the efficiency of the system.

This table summarizes my findings. 

10March3014

A Heat Engine Using A Simple Gas Cycle 

The theoretical analysis of a heat engine that shows the process of a isobaric and isovolumetirc system.  The change in internal energy, heat, and work was calculated in the above picture based on the pressure volume and temperature given at each point. 

The Mass Lifter Heat Engine

This picture shows the relationship between a isotherm and adiabatic process in a engine. Given the pressure temperature and volume at each different point in the cycle we were able to calculate the change in internal energy, heat, and work. Using the total work and the heat that goes into the system we determined the the systems efficiency was 33 %.

Activphysics 8.7 Heat Capacity

Queston 6: The change in temperature was monitored in order to calculate the constant pressure molar heat capacity. Our rough estimations said that Cp=20.4J/(mol*K).

Question 7: The change in temperature from 200K to 800K was monitored in order to calculate the constant pressure molar heat capacity. Our rough estimations said that Cp=20.8J/(mol*K).

Question 8 shows the derivation of the constant pressure molar heat capacity from the change in the internal energy of a isobaric process. 

5Mar2013

The Fire Syringe-Fahrenheit 451

The purpose of this experiment was used to calculate the final temperature after the fire syringe was depressed rapidly. The fire syringe is insulated so that there is no heat transfer when the reaction occurs there for Q=0. By taking the length measurement of the air column before the depression and after and the inner radius of the tube we were able to calculate the initial and final volume. We measured the temperature of the room and used the formula above to calculate the final volume which is 1641.44 K(the K for kelvins got cut off in the picture). The we converted it to fahrenheit 2494.2 degrees Fahrenheit. 

We expected to see a burst of flames when rapidly depressing the plunger here is the video which fit our prediction.  I was unable to orient the video properly for the next experiment I will properly orient the video. 

State Variable and Ideal Gas Law

This picture represents the calculations for the 6 questions in this lab. 

Question 1 is a graph of linear relationship of volume verses temperature for a isobaric process in which pressure is held constant. 

Question 2 is a graph of the linear relationship of pressure verses temperature for a isochoric process in which volume is held constant. 

Question 3 is a graph of the non-linear relationship of pressure verses volume  when temperature is held constant which is a isothermal process. 

Questions 4,5, and 6 are reviewed below with the activity image but the calculations for these pictures can be seen in the picture above. 

Question 4 is a calculation for the volume of the container when the temperature is reduced to 301.8 K in a isobaric process. V(final)=25.09 dm^3

Question 5 is a calculation for the pressure in the container when the temperature is increased to 300K in a isochoric process. P(final)= 124.7kPa

Question 6 is a calculation for the pressure in the container when the volume is decreased to 10 dm^3 in a isothermal process.  P(final)= 124.7kPa

Lab Monday 3March2014

V vs. T for a Gas (Charles’ Law l)

 The syringe is placed into the flask and initial volume of the flask is recorded by taking a measurement of the mass and multiplying it by the density. The flask was placed into a bath of room temperature water  and volume of the syringe was recorded. The Temperature was recorded in logger pro. This was done so we can create three sets of data points to graph the relationship between Volume and Temperature and find the coefficient of their linear relationship.

This is a picture of the flask in a hot water bath and it illustrated how when the temperature increased the volume of the syringe increased. The opposite occurred for the ice bath, the volume decreased with a decrease in temperature.

 We expect that the relationship between volume and temperature is linear and our prediction is seen in this graph. The number of grams used to fill the flask to the stopper was determined on a analytical balance to be 142.1 g or 142.1 cc.  The data we collected gave us three points we can plot on a V vs T graph. One ordered pair for initial conditions at room temperature, cooling, and heating.

The reason the pressure of the air remains constant even though the volume changes is due to their inversely proportional relationship with volume and directly proportional relationship with temperature. P=(constant ) T/V as the volume and temperature change the pressure remains the same this can be seen when the ideal law is manipulated by dividing by the volume.  

V and T are linearly related and the slope of this graph was calculated in excel to be 0.312.

To understand the units of the slope we can manipulate the ideal gas law as seen above. We find the units of the coefficient to be 0.312 cc/K.