Homework B: Due Friday, Feb 14, 2014 at conference. Instructions: Please provide a brief verbal explanation of each step in your solution. State where the formulas are coming from, and why they are applicable here. Use symbols and formulae effectively defining their meaning and making it clear whether they are vectors or scalars. Write legibly, and draw large and clearly labeled sketches. Here is a problem that will let you both practice Gauss’s Law and help you see how more complicated systems can be built from the simpler ones. More complicated systems cannot be solved by themselves with Gauss’s Law, but the simpler ones can, and then you can use the principle of superposition to put everything together. (a) An infinite plate with thickness 2h is parallel to the x − z plane so that it’s mid-point (the point halfway through the plate) is at y = 0. (That way all the points on one surface have y = +h and on the other y = −h.) The plate is uniformly charged with volume charge density +ρ. Sketch the electric field lines. Using a cylinder of height 2y and base area A as a Gaussian surface, find the magnitude of the electric field for any value of y. Graph Ey(y) (the projection of ~E onto the y axis). Finally, express ~E(x,y,z) using the unit vectors of Cartesian coordinate system: î, ĵ, and k̂. (b) An infinite cylinder with outer radius h is coaxial with the z axis. It is uniformly charged with the volume charge density +ρ. Using a cylinder of radius r and length ` (also coaxial with the z axis) as the Gaussian surface, derive E(r). Graph E(r). Express ~E(r) using the unit vector r̂ of the vector ~r, drawn from the z axis to the point where we want the electric field. Next, express ~E(x,y,z) as a function of î, ĵ, and k̂. [Note: If we label the azimuthal angle of the cylindrical coordinate system with φ, then ~r = xî + yĵ = r cos φî + r sin φĵ and thus r̂ = cos φî + sin φĵ.] (c) Through an infinite charged plate described in part (a), an infinitely long cylindrical hole of radius h is drilled so that it is coaxial with the z axis. [Note the cylinder axis of the hole is parallel to the plane. The system consists of a plate from part (a) with the cylinder from part (b) taken away. ] Using the principle of superposition, and relying on the answers from parts (a) and (b), explain in words how we can get an electric field at an arbitrary point. For the points along the y axis, graph Ey(y). Write a formula for ~E at an arbitrary point (x,y,z). 1 Name: Date: Instructor’s Name: Assignment: SCIE207 Phase 2 Lab Report Title: Animal and Plant Cell Structures Instructions: Your lab report will consist of the completed tables. Label each structure of the plant and animal cell with its description and function in the tables provided. When your lab report is complete, post it in Submitted Assignment files. 1. Animal Cell: Observe the diagram showing the components of an animal cell. Using the textbook and virtual library resources,.

1. Homework B: Due Friday, Feb 14, 2014 at conference.
Instructions: Please provide a brief verbal explanation of each
step in your solution. State
where the formulas are coming from, and why they are
applicable here. Use symbols and
formulae effectively defining their meaning and making it clear
whether they are vectors or
scalars. Write legibly, and draw large and clearly labeled
sketches.
Here is a problem that will let you both practice Gauss’s Law
and help you see how more
complicated systems can be built from the simpler ones. More
complicated systems cannot
be solved by themselves with Gauss’s Law, but the simpler ones
can, and then you can use
the principle of superposition to put everything together.
(a) An infinite plate with thickness 2h is parallel to the x − z
plane so that it’s mid-point
(the point halfway through the plate) is at y = 0. (That way all
the points on one
surface have y = +h and on the other y = −h.) The plate is
uniformly charged with
volume charge density +ρ. Sketch the electric field lines. Using
a cylinder of height
2y and base area A as a Gaussian surface, find the magnitude of
the electric field for
any value of y. Graph Ey(y) (the projection of ~E onto the y
axis). Finally, express
~E(x,y,z) using the unit vectors of Cartesian coordinate system:

2. î, ĵ, and k̂ .
(b) An infinite cylinder with outer radius h is coaxial with the z
axis. It is uniformly
charged with the volume charge density +ρ. Using a cylinder of
radius r and length
` (also coaxial with the z axis) as the Gaussian surface, derive
E(r). Graph E(r).
Express ~E(r) using the unit vector r̂ of the vector ~r, drawn
from the z axis to the
point where we want the electric field.
Next, express ~E(x,y,z) as a function of î, ĵ, and k̂ .
[Note: If we label the azimuthal angle of the cylindrical
coordinate system with φ, then
~r = xî + yĵ = r cos φî + r sin φĵ and thus r̂ = cos φî + sin φĵ.]
(c) Through an infinite charged plate described in part (a), an
infinitely long cylindrical
hole of radius h is drilled so that it is coaxial with the z axis.
[Note the cylinder axis
of the hole is parallel to the plane. The system consists of a
plate from part (a) with
the cylinder from part (b) taken away. ]
Using the principle of superposition, and relying on the answers
from parts (a) and
(b), explain in words how we can get an electric field at an
arbitrary point.
For the points along the y axis, graph Ey(y).
Write a formula for ~E at an arbitrary point (x,y,z).

3. 1
Name:
Date:
Instructor’s Name:
Assignment: SCIE207 Phase 2 Lab Report
Title: Animal and Plant Cell Structures
Instructions: Your lab report will consist of the completed
tables. Label each structure of the plant and animal cell with its
description and function in the tables provided.
When your lab report is complete, post it in Submitted
Assignment files.
1. Animal Cell: Observe the diagram showing the components
of an animal cell. Using the textbook and virtual library
resources, fill in the following table:
Animal Cell
Number
Cell Structure
Description and Function
1
2
3
4

4. 5
6
7
8
9
10
11
12
13
14
15
16

5. 17
18
19
20
2. Plant Cell: Observe the diagram showing the major
components of a plant cell. Using the textbook and virtual
library resources fill in the following table:
Plant Cell
Number
Cell Structure
Description and Function
1
2
3
4
5

6. 6
7
8
9
10
11
12
13
14
15
16
17

7. 18
19
When your lab report is complete, post it in Submitted
Assignment files.