Flux/Gauss's Law(Update)

In the class period we talked all about flux. We started off with a simple flux conseptual problem with flux lines and surfaces. We then moved on to the actual equation of the flux lines and what we had to do to find them.

Here is a conspetual problem that we did to start off the class. It is three electrons with different q charges which chanages the amount of lines that is expelled out of each charge. We went over what it ment to have flux through a given area. This is a 2D diagram but in pratical life it is in fact 3-dimential.

We had to describe the meaning of flux. My group said flux was teh difference between the number of lines in and out a surface area. It was also proportional to the charge enclosed by that surface area.

We had the great idea to put many different things inside a microwave and see what happens. We put a fork in the microwave thinking that it will have sparks at the tips but it actually did not do anything.

We later put a CD inside the microwave and the sparks flew. Bubbles of sparks and maybe plasma erupted in an amazing display of color.

We predicted that sparks would fly when the CD was left in the micro way while it was on. We also had a grape and Christmas ordainment in the microwave and sparks flew with both of them depending on how the objects were orientated inside the microwave.

This was the results of the second time i was in the class. As suspected it cracked or broke the bonds that were layer over the backside of the CD.

This is a movie of the time we put the light bulb into the microwave. I don't know if  the video will show. This is the first time I am doing it and it might just be a blank bock. Or nothing at all.

This is the equation for a given sphere that has a change of radius dr. It is a farily simple intergal but there is a cubic factor that we needed to take into consideration.

Here we see that the flux could be writen as an E equation that we already learned in the previous class session. It was a good connection point.

The Five problems from Activphysics that were both enlightening and confusing at the same time. I wish we had a longer time to go over Gausses law and Flux

This is a equation that we will be using over a perid of time probably or maybe not since we are having the test next class period.

This has to do with a diffusion of a charge through a cylinder.

Along with that equation we have this one that shows us what step by step nature of the cylinder.

It was a very simple equations once you understood the underlining principle.

This is the simple downed version on what coefficient of any object. We use a Y because it was free and its for any object.  

This was given for the question of finding the earths Gauss or was it flux?

Introduction to Gauss's Law(Update)

This was the second day that we went over eletromagnetics in call. I will talk about what happends in a eletromagnetic field, what happens inside a Faraday Cage, and the field that two eletrons create when they are near each other along with other more advance equations. We will create a more elabrate understanding of the little game that we played at the end of the last blog post.

Here we can see how a negatively charge electron travels when it goes through a Electronmagnetic field. Depending on how fast the electron is moving it will make it across the field or colid with the positive side. Here my group prediced that the electron was moving fast enough to make it across. Since the negative charge is attracted to the positive side it will curve downward after leaving the field.

Here we where asked to to show what we should do if we were in the middle of a lighting storm and was in a car. I personally thought we should have went outside with our embrallas course, and enjoy the sight. Its a once in a life time experience; however, my group thought it would be a better idea to stay inside the car. They said it was something about Gauss's Law and/or Faraday cages.

Well if fact they are right since if you are in the car the lighting will not go through the car. Well it will not shock anyone inside the car and instead will stay on the outside and be grounded to earth.

We are introduced to torsen (a.k.a torque) inside a Electromagnetic field between two point charges. It is a farily simple equations; as seen below.

This is the equations for torsen. All that is needed is the Force (F) that each electron is producing on each other, the distance (r) from each other, and the angle with respect to the x-axis. This is a simple  Physics 2A problem just with electrons.

Now this is something that i hope that is not on the test on Thursday since I am still very unfamilar with the processes need to achieve the right answer.

We are being introduced to a Faraday Cage. This is were we predicted what will happen to the two square strips of foil papers. We thought it was going to push the foil away from the cage in both directions but we were wrong.

This is what really happen. This picture is also drawn out below since it is quite blurry.

This was what my group picked the first time I was in the class.

This was the option that my grouped picked the second time.

Both options were identical though I did not put much input the second time because I wanted my group to have the same experience I had when i first do the exercise.

Faraday Cage

This is how a possitve and negative charge electron react to each other. They create a field all around they pulling and pushing electrons that get near they. This what was happening in the little game we did last lecture period.

This is a follow-up to the picture of the red and blue electrons. Here we see the field that hone electron makes by itself. Also we see the field that two electron makes when they are opposite from each other. We also see that there is no E if you make a circular path around both of the electrons. That means that there is a net change of zero. In the picture of only one electron there is a E of zero also since it is equaly defused. This is what we call Flux.

These were the answers of the questions for the little lab that we did on the computer. I understand the flux concept but I will need to practice the are formula because it will get really complicated later.

Electric Fields(Update: Vpython)

Like with anything the best way to learn something new is to connect it to something one alreay knows. Here we took what we learned about gravity and transformed it ton electri fields. We wrote down how the field is created, what the magnitude of the field depends on, how distance effects the magnitude of the field and what a charge will experience when it is in an electric field.

These are the physical equations comparming the previous statements of the above picture. The force, the electric field, the form of the field and how it is all respected to the distance, direction, and magnitude.

The two different impressions on the plastic sheet is a "physical representation" of how negative and postive electrons creates a field. The positive pushes away objects so it has a hill representation; while a negative electron has a pulling function so it has a vallly type of a representation. These are just easy to understand representations. This is not the only factor in what causes two elements to be attracted to each other.

This is a set of pre-determined calculations off of an sent of values. The only thing that is changing is the radius of the function. The further the two charges are from each other the less they react to each other's charges.

These are some basic calculations of the eletric field or the system of three charges. This is just like an 2A equation of forces just now just with electrons.

This is a more complucated version of what was show above. It has to do e with different angles and distances. However, the calculations were fairly simple due to the predetermined calculations we did on Exel (shown below). Each charge effected all the other three charges.

This is the Excel document that we used to cacluate what we needed; which was the Electic field.

Here we are intoduced the to a calculus version of what we have been doing. This is just a bar of charge acting on a point charge in teh z-axis. This is the most simple problem that we can do in point charge and a mass of charge.

Here is the final equation of the day. This is what we were doing in the previous picture above but with a charge to the left of the rod at a certain distance.

The following pictures is the conformation of the little mini game with charges. We will go over more about this in the next lecture so I will be talking about his in the next blog so stay tune.



Goal!!

Goal!!

Goal!!

Instead of doing the hockey simulation we did Vpython. 

This is what the original code would have looked like if we did not change the code that was given to use my Prof. Mason. It was very simple in practice. The code that made this image is below.

This code is what we made with some help from Mason during class. We changed the direction and the size of each arrow to best represent what we had.

from visual import *

## CONSTANTS

k = 9e9   ## OneOverFourPiEpsilonZero

q1 = 1.6e-19

## OBJECTS

particle = sphere(pos=vector(1e-10, 0, 0), radius = 2e-11, color=color.red)

xaxis = cylinder(pos=(-5e-10,0,0), axis=vector(10e-10,0,0),radius=.2e-11)

yaxis = cylinder(pos=(0,-5e-10,0), axis=vector(0,10e-10,0),radius=.2e-11)

zaxis = cylinder(pos=(0,0,-5e-10), axis=vector(0,0,10e-10),radius=.2e-11)

## the position of the arrow is the observation location:

Earrow1 = arrow(pos=vector(3.1e-10,-2.1e-10,0), axis = vector(1e-10,0,0), color=color.orange)

Earrow2 = arrow(pos=vector(3.1e-10,2.1e-10,0), axis = vector(1e-10,0,0), color=color.orange)

Earrow3 = arrow(pos=vector(-1.1e-10,-2.1e-10,0), axis = vector(1e-10,0,0), color=color.orange)

Earrow4 = arrow(pos=vector(-1.1e-10,2.1e-10,0), axis = vector(1e-10,0,0), color=color.orange)

Earrow5 = arrow(pos=vector(1e-10,0,3e-10), axis = vector(1e-10,0,0), color=color.orange)

Earrow6 = arrow(pos=vector(1e-10,0,-3e-10), axis = vector(1e-10,0,0), color=color.orange)

## CALCULATIONS

R1=Earrow1.pos-particle.pos

R2=Earrow2.pos-particle.pos

R3=Earrow3.pos-particle.pos

R4=Earrow4.pos-particle.pos

R5=Earrow5.pos-particle.pos

R6=Earrow6.pos-particle.pos

Ef1=((k*q1)/(mag(R1)**3))

Ef2=((k*q1)/(mag(R2)**3))

Ef3=((k*q1)/(mag(R3)**3))

Ef4=((k*q1)/(mag(R4)**3))

Ef5=((k*q1)/(mag(R5)**3))

Ef6=((k*q1)/(mag(R6)**3))

## write instructions below to tell the computer how to calculate the correct

## electric field E1 at the observation location (the position of Earrow1):

## change the axis of Earrow1 to point in the direction of the electric field at that location

## and scale it so it looks reasonable

scalefactor= 1e-20

Earrow1.axis= Ef1*R1*scalefactor

Earrow2.axis= Ef2*R2*scalefactor

Earrow3.axis= Ef3*R3*scalefactor

Earrow4.axis= Ef4*R4*scalefactor

Earrow5.axis= Ef5*R5*scalefactor

Earrow6.axis= Ef6*R6*scalefactor

print "Ef1: ", Ef1

print "Ef2: ", Ef2

print "Ef3: ", Ef3

print "Ef4: ", Ef4

print "Ef5: ", Ef5

print "Ef6: ", Ef6

## additional observation locations; do the same thing for each one

The output is such.

Our next time we use Vpython we had a cool picture both in 2D and 3D but we dont have the picture of it right now. Here is the code for it. We were just representing the motion that a small positive charge would move if it was near a charge. The image is really cool.

from __future__ import division from visual import * ## constants k = 9e9 # stands for One Over Four Pi Epsilon-Zero qe = 1.6e-19 # proton charge s = 4e-11 # charge separation R = 3e-10 # display Enet on a circle of radius R V = 2e-10 scalefactor = 1e-20 # for scaling arrows to represent electric field ## objects ## Represent the two charges of the dipole by red and blue spheres: plus = sphere(pos=vector(s/2,0,0), radius=1e-11, color=color.red) qplus = qe # charge of positive particle neg = sphere(pos=vector(-s/2,0,0), radius=1e-11, color=color.blue) qneg = -qplus # charge of negative particle ## calculations theta = 0 while theta < 2*pi: rate(50) # tell computer to go through loop slowly ## Calculate observation location (tail of arrow) using current value of theta: Earrow1 = arrow(pos=R*vector(cos(theta),sin(theta),0), axis=vector(1e-10,0,0), color=color.orange) R1= Earrow1.pos-plus.pos R2= Earrow1.pos-neg.pos Ef1=((k*qplus)/(mag(R1)**3)) Ef2=((k*qneg)/(mag(R2)**3)) Earrow1.axis= ((Ef1*R1)+(Ef2*R2))*scalefactor print "Ef1: ", Ef1 ## write instructions below to tell the computer how to calculate the correct ## net electric field Enet at the observation location (the position of Earrow): ## change the axis of Earrow to point in the direction of the electric field at that location ## and scale it so it looks reasonable ## Assign a new value to theta theta = theta + pi/12 theta = 0 while theta < 2*pi: rate(50) # tell computer to go through loop slowly ## Calculate observation location (tail of arrow) using current value of theta: Earrow1 = arrow(pos=R*vector(cos(theta),0,sin(theta)), axis=vector(1e-10,0,0), color=color.orange) R1= Earrow1.pos-plus.pos R2= Earrow1.pos-neg.pos Ef1=((k*qplus)/(mag(R1)**3)) Ef2=((k*qneg)/(mag(R2)**3)) Earrow1.axis= ((Ef1*R1)+(Ef2*R2))*scalefactor print "Ef1: ", Ef1 ## write instructions below to tell the computer how to calculate the correct ## net electric field Enet at the observation location (the position of Earrow): ## change the axis of Earrow to point in the direction of the electric field at that location ## and scale it so it looks reasonable ## Assign a new value to theta theta = theta + pi/12 theta = 0 while theta < 2*pi: rate(50) # tell computer to go through loop slowly ## Calculate observation location (tail of arrow) using current value of theta: Earrow1 = arrow(pos=R*vector(0,cos(theta),sin(theta)), axis=vector(1e-10,0,0), color=color.orange) R1= Earrow1.pos-plus.pos R2= Earrow1.pos-neg.pos Ef1=((k*qplus)/(mag(R1)**3)) Ef2=((k*qneg)/(mag(R2)**3)) Earrow1.axis= ((Ef1*R1)+(Ef2*R2))*scalefactor print "Ef1: ", Ef1 ## write instructions below to tell the computer how to calculate the correct ## net electric field Enet at the observation location (the position of Earrow): ## change the axis of Earrow to point in the direction of the electric field at that location ## and scale it so it looks reasonable ## Assign a new value to theta theta = theta + pi/12 theta = 0 scalefactor= 1*(10**(-20.5)) while theta < 2*pi: rate(50) # tell computer to go through loop slowly ## Calculate observation location (tail of arrow) using current value of theta: Earrow1 = arrow(pos=V*vector(cos(theta),sin(theta),0), axis=vector(1e-10,0,0), color=color.red) R1= Earrow1.pos-plus.pos R2= Earrow1.pos-neg.pos Ef1=((k*qplus)/(mag(R1)**3)) Ef2=((k*qneg)/(mag(R2)**3)) Earrow1.axis= ((Ef1*R1)+(Ef2*R2))*scalefactor print "Ef1: ", Ef1 ## write instructions below to tell the computer how to calculate the correct ## net electric field Enet at the observation location (the position of Earrow): ## change the axis of Earrow to point in the direction of the electric field at that location ## and scale it so it looks reasonable ## Assign a new value to theta theta = theta + pi/12 theta = 0 while theta < 2*pi: rate(50) # tell computer to go through loop slowly ## Calculate observation location (tail of arrow) using current value of theta: Earrow1 = arrow(pos=V*vector(cos(theta),0,sin(theta)), axis=vector(1e-10,0,0), color=color.red) R1= Earrow1.pos-plus.pos R2= Earrow1.pos-neg.pos Ef1=((k*qplus)/(mag(R1)**3)) Ef2=((k*qneg)/(mag(R2)**3)) Earrow1.axis= ((Ef1*R1)+(Ef2*R2))*scalefactor print "Ef1: ", Ef1 ## write instructions below to tell the computer how to calculate the correct ## net electric field Enet at the observation location (the position of Earrow): ## change the axis of Earrow to point in the direction of the electric field at that location ## and scale it so it looks reasonable ## Assign a new value to theta theta = theta + pi/12 theta = 0 while theta < 2*pi: rate(50) # tell computer to go through loop slowly ## Calculate observation location (tail of arrow) using current value of theta: Earrow1 = arrow(pos=V*vector(0,cos(theta),sin(theta)), axis=vector(1e-10,0,0), color=color.red) R1= Earrow1.pos-plus.pos R2= Earrow1.pos-neg.pos Ef1=((k*qplus)/(mag(R1)**3)) Ef2=((k*qneg)/(mag(R2)**3)) Earrow1.axis= ((Ef1*R1)+(Ef2*R2))*scalefactor print "Ef1: ", Ef1 ## write instructions below to tell the computer how to calculate the correct ## net electric field Enet at the observation location (the position of Earrow): ## change the axis of Earrow to point in the direction of the electric field at that location ## and scale it so it looks reasonable ## Assign a new value to theta theta = theta + pi/12

Electric Charges(Update)

 

This is the begining of a new section of the book. It is no more about thermal expanssion. It is all about positive and negative charge electrons and how they react to each other directily and indirectly. So lets change our focus to back to 2A becaue a lot of the elements that has to do with electrons resembles simple free body diagrams and sum of forces for now.

 

 

In thi picture we see what happens to a balloon  that was rummbed with mystery fur. The fur most likly came from a road kill rabbit or something in the rabbit family. However, that is not the point of the picture. Here we see that the balloon sticks to the surface of the glass just because the balloon was rubbed with the rabbit fur.

 

Here is the free body diagram of the forces acting on the balloon when it is stuck to the wall and not falling. The new force that we have not seen in previous physics classes is the Force of electron magnetisim.

 

Here we are doing a little lab. We stucked two long pieces of tape on the table and quickly pulled them off. Then we slowling place the to non-sticky sides to each other and saw that they were moving away from each other as we tried to get the two pieces closer.

 

Here we are doing a simple force problem with a charge attacted to a string while another one is getting closer and closer. We obtain data through Logger Pro ( as seen below).

 

We needed to create new calculated columes to be able to graph the proper graph. We need to measure the inital distance of the two charges and the final hight that the charge on the string ended up.

 

This is the equations that we used to cacluate the charges of an two electrons. It was based out of what the area and the radius of each  electron.

 

This picture shows the three ways that electrons act wiith each other. And that is it for this picture. It is just for reference/ memorization of what the charges sign should be and conceptual what shoudl happen so you can see if your answer is right.

 

Here we caclualted that force of a electron onto another electron. F=Kq1q2/r^2.

The most simple electron force equation that we will use in this class.

 

here we see the same problem but now with angles and we needed to find the magnetude of the force in the particular direction. It is the basic x^2=y^2=z^2

 

Here we see a wig on a qutomated fur rubber. That is not the offical name of the contraption but it will have to do for now. This creates electric charges that causes the hair to stand on end.

 

here is the picture of the guts of the contraption. We had to describe how it was created the charge. This year we did the samething but with actual hear. It had a similar effect.

Here we see that the force of an electric charge is 42 times stronger then the force of gravity. Which means if two electrons the size of the earth was made it will be stronger then the sun. I think anyway.