184_projects:f20_project_4

Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revision Previous revision
Next revision		 Previous revision
184_projects:f20_project_4 [2020/08/23 19:23] – dmcpadden184_projects:f20_project_4 [2020/09/26 19:30] (current) – dmcpadden
Line 1: Line 1:
 ===== Project 4 ===== ===== Project 4 =====
-==== Project 4A: Mini-Particle Accelerator  ====+==== Project 4A: Maverick's Wires  ====
  
-S.P.A.R.T.A.N force, still trapped in the town of Lakeview, has been sent as part of a larger governmental team to work on developing a micro-particle accelerator on the outskirts of town. Why does a town the size of Lakeview need a micro-particle accelerator? You are not at liberty to say. Your team is tasked with modeling the initial part of the accelerator, which uses a constant electric field to accelerate the charges. The concept is that the particles will enter a tube that is encapsulated by rings of charge. Your team needs to demonstrate that this concept will produce a __constant__ electric field. +Outside of the town of Lakeview work is being completed on the Artemis 13 spacecraft. Another engineering and science task force titled T.R.O.J.A.N force are working with The Jet Propulsion Laboratory (JPL) Division of NASA testing a new and highly experimental spacecraft capable of in atmosphere flight as well as outer orbit maneuvering (Artemis 13). Lieutenant Pete "Maverick" Mitchell has been testing the new spacecraft now for a few weeks, including a detailed look at all the wiring in the spacecraft. His crew has been creating a model of the wire using multiple rings of charge, but they are having a difficult time justifying where the __constant__ electric field in the wire comes from. Initially, the crew created a model of the wire consisting of multiple rings, all with the same charge. But, the field doesn't look quite right - it's not constant as expected. It's up to you to adjust the code so that it models a constant electric field.
- +
-== Part 1: == +
-The first bit of code that you have received is from the previous team who were able to construct a single ring of charge and show the electric field due to that ring at some point. Your team should construct the electric field vectors for a circle inside the accelerator (smaller than the ring) at a distance of a few centimeters from the ring face. +
- +
-<code> +
-GlowScript 2.7 VPython +
-#Set up constants +
-R = 0.02 +
-r_obs = 0.05 +
- +
-Q = 1e-9  +
-N = 20 +
-dq = Q/N +
- +
-scale=1e-4 +
-oofpez = 9e9 #1/(4pi epsilon_0) in N m^2/C^2 +
- +
-#Defining a ring at the origin +
-myring = ring(pos = vector(0,0,0), radius = R, axis = vector(0,0,1), color = color.blue, thickness = 0.02*R) +
- +
-#Create an empty list for the charges +
-ChargeList=[] +
- +
-#Set up the step size and angle for creating the charges +
-dtheta = 2*pi/N  +
-theta = dtheta/2  +
- +
-#Create charges in a circle and add them to the ChargeList +
-while theta < 2*pi: +
-    rpiece = R*vector(cos(theta),sin(theta),0) #location of piece +
-     +
-    particle = sphere(pos = rpiece, radius = R/20, color = color.yellow) +
-    ChargeList.append(particle) +
-         +
-    theta = theta + dtheta +
- +
-#Create an empty list for the observation points +
-ObsList = [] +
- +
-#Set up the step size and angle for creating the observation points +
-phi = 0 +
-dphi = pi/4 +
- +
-#Create charges in a circle and add them to the ObsList +
-while phi < 2*pi: +
-    r_obs_piece = r_obs*vector(cos(phi),sin(phi),1) #location of piece +
-     +
-    obs_particle = sphere(pos = r_obs_piece, radius = R/20, color = color.red) +
-     +
-    ObsList.append(obs_particle) +
-         +
-    phi = phi + dphi +
- +
-#Find the electric field at each observation point +
-for obs_point in ObsList: +
-         +
-    for charge in ChargeList: +
-        Enet=vec(0,0,0)      +
-</code> +
- +
-== Part 2 == +
- +
-After you got this initial code working, your team was able to construct a model of a tube consisting of multiple rings, all with the same charge. But, the field doesn't look quite right - it's not constant as expected. Your bosses seem to think the field can be made constant in the tube, so it's up to you to figure out how. +
  
 <code> <code>
Line 128: Line 65:
     Evector=arrow(pos=rpoint, axis=scale*Enet, color=color.orange, shaftwidth=apoint.radius/2)     Evector=arrow(pos=rpoint, axis=scale*Enet, color=color.orange, shaftwidth=apoint.radius/2)
 </code> </code>
 +
 +<WRAP info>
 +=== Learning Goals ===
 +  * Explain what a "constant electric field" means
 +  * Explain what a "surface charge gradient" is in context of a wire
 +  * Explain how a surface charge gradient creates a constant electric field
 +</WRAP>
  
 ==== Project 4B: Maverick and JPL ==== ==== Project 4B: Maverick and JPL ====
Line 146: Line 90:
   * Explain why a lightbulb would not turn on if it were only connected to the positive end of the battery.   * Explain why a lightbulb would not turn on if it were only connected to the positive end of the battery.
   * Explain the role of the battery in lighting up the lightbulb.   * Explain the role of the battery in lighting up the lightbulb.
 +</WRAP>
 +
 +==== Project 4C: Maverick and the Crossed Wires ====
 +{{  184_notes:split_wire.png?300}}
 +Maverick has been sufficiently convinced that the warning light cannot possibly take too long. Good job! In the meantime, his inspection of the wires has revealed a slight inconsistency in the circuit. It appears that half of the wiring is made from a 12-gauge copper wire and half is made from an 18-gauge copper wire. Maverick is worried about the affect this will have on the circuit. He has asked your team to report the effects of the different sized wires on the electric field, the surface charges, and the current in the wires.
 +
 +<WRAP info>
 +=== Learning Goals ===
 +  * Explain what happens to the current in a circuit with different sized wires
 +  * Explain what happens to the electric field in a circuit with different sized wires
 +  * Explain what happens to the surface charge gradient in a circuit with different sized wires
 +  * Explain how the current, electric field, and surface charge gradient are related
 </WRAP> </WRAP>
  • 184_projects/f20_project_4.1598210624.txt.gz
  • Last modified: 2020/08/23 19:23
  • by dmcpadden