From 7b32eaf495c8e6e32222edb3d2d2f5ef3c499092 Mon Sep 17 00:00:00 2001
From: "W. Trevor King" <wking@drexel.edu>
Date: Mon, 29 Jun 2009 15:28:36 -0400
Subject: [PATCH] Added problem text for recitation weeks 1&2 of Summer 2009's
 PHYS 102

---
 .../Young_and_Freedman_12/problem21.34.tex    | 12 ++++++++++
 .../Young_and_Freedman_12/problem21.47.tex    | 10 ++++++++
 .../Young_and_Freedman_12/problem21.72.tex    | 12 ++++++++++
 .../Young_and_Freedman_12/problem21.74.tex    | 13 ++++++++++
 .../Young_and_Freedman_12/problem21.76.tex    | 24 +++++++++++++++++++
 .../Young_and_Freedman_12/problem21.81.tex    | 11 +++++++++
 .../Young_and_Freedman_12/problem22.16.tex    |  9 +++++++
 .../Young_and_Freedman_12/problem22.18.tex    | 13 ++++++++++
 .../Young_and_Freedman_12/problem22.23.tex    | 13 ++++++++++
 .../Young_and_Freedman_12/problem22.25.tex    | 11 +++++++++
 .../Young_and_Freedman_12/problem22.37.tex    | 16 +++++++++++++
 latex/rec/rec1/all_problems.tex               |  9 ++++---
 latex/rec/rec1/problem1.tex                   |  2 +-
 latex/rec/rec1/problem2.tex                   |  2 +-
 latex/rec/rec1/problem3.tex                   |  2 +-
 latex/rec/rec1/problem4.tex                   |  2 +-
 latex/rec/rec1/problem5.tex                   |  2 +-
 latex/rec/rec1/problem6.tex                   |  1 +
 latex/rec/rec1/problem7.tex                   |  1 +
 latex/rec/rec1/problem8.tex                   |  1 +
 20 files changed, 158 insertions(+), 8 deletions(-)
 create mode 100644 latex/problems/Young_and_Freedman_12/problem21.34.tex
 create mode 100644 latex/problems/Young_and_Freedman_12/problem21.47.tex
 create mode 100644 latex/problems/Young_and_Freedman_12/problem21.72.tex
 create mode 100644 latex/problems/Young_and_Freedman_12/problem21.74.tex
 create mode 100644 latex/problems/Young_and_Freedman_12/problem21.76.tex
 create mode 100644 latex/problems/Young_and_Freedman_12/problem21.81.tex
 create mode 100644 latex/problems/Young_and_Freedman_12/problem22.16.tex
 create mode 100644 latex/problems/Young_and_Freedman_12/problem22.18.tex
 create mode 100644 latex/problems/Young_and_Freedman_12/problem22.23.tex
 create mode 100644 latex/problems/Young_and_Freedman_12/problem22.25.tex
 create mode 100644 latex/problems/Young_and_Freedman_12/problem22.37.tex
 create mode 120000 latex/rec/rec1/problem6.tex
 create mode 120000 latex/rec/rec1/problem7.tex
 create mode 120000 latex/rec/rec1/problem8.tex

diff --git a/latex/problems/Young_and_Freedman_12/problem21.34.tex b/latex/problems/Young_and_Freedman_12/problem21.34.tex
new file mode 100644
index 0000000..e602051
--- /dev/null
+++ b/latex/problems/Young_and_Freedman_12/problem21.34.tex
@@ -0,0 +1,12 @@
+\begin{problem*}{34}
+Point charge $q_1=-5.00\U{nC}$ is at the origin and point charge
+$q_2=+3.00\U{nC}$ is on the $x$-axis at $x=3.00\U{cm}$.  Point $P$ is
+on the $y$-axis at $y=4.00\U{cm}$.  \Part{a} Calculate the electric
+fields $\vec{E}_1$ and $\vec{E}_2$ at point $P$ due to charges $q_1$
+and $q_2$.  Express your results in terms of unit vectors (see Example
+21.6).  \Part{b} Use the results of \Part{a} to obtain the resultant
+field at $P$, expressed in unit vector form.
+\end{problem*}
+
+\begin{solution}
+\end{solution}
diff --git a/latex/problems/Young_and_Freedman_12/problem21.47.tex b/latex/problems/Young_and_Freedman_12/problem21.47.tex
new file mode 100644
index 0000000..9b2c7b0
--- /dev/null
+++ b/latex/problems/Young_and_Freedman_12/problem21.47.tex
@@ -0,0 +1,10 @@
+\begin{problem*}{47}
+Three negative point charges lie along a line as shown in Fig.~21.40.
+Find the magnitude and direction of the electric field this
+combination of charges produces at point $P$, which lies $6.00\U{cm}$
+from the $-2.00\U{$\mu$C}$ charge measured perpendicular to the line
+connecting the three charges.
+\end{problem*}
+
+\begin{solution}
+\end{solution}
diff --git a/latex/problems/Young_and_Freedman_12/problem21.72.tex b/latex/problems/Young_and_Freedman_12/problem21.72.tex
new file mode 100644
index 0000000..bc33088
--- /dev/null
+++ b/latex/problems/Young_and_Freedman_12/problem21.72.tex
@@ -0,0 +1,12 @@
+\begin{problem*}{72}
+A charge $q_1=+5.00\U{nC}$ is placed at the origin of an
+$xy$-coordinate system, and a charge $q_2=-2.00\U{nC}$ is placed on
+the positive $x$-axis at $x=4.00\U{cm}$.  \Part{a} If a third charge
+$q_3=+6.00\U{nC}$ is now placed at the point $x=4.00\U{cm}$,
+$y=3.00\U{cm}$, find the $x$- and $y$-components of the total force
+exerted on this charge by the other two.  \Part{b} Fund the magnitude
+and direction of this force.
+\end{problem*}
+
+\begin{solution}
+\end{solution}
diff --git a/latex/problems/Young_and_Freedman_12/problem21.74.tex b/latex/problems/Young_and_Freedman_12/problem21.74.tex
new file mode 100644
index 0000000..794ad09
--- /dev/null
+++ b/latex/problems/Young_and_Freedman_12/problem21.74.tex
@@ -0,0 +1,13 @@
+\begin{problem*}{74}
+Two identical spheres with mass $m$ are hung from silk threads of
+length $L$ as shown in Fig.~21.44.  Each sphere has the same charge,
+so $q_1=q_2=q$.  The radius of each sphere is very small compared to
+the distance between the spheres, so they may be treated as point
+charges.  Show that if the angle $\theta$ is small, the equilibrium
+separation $d$ between the spheres is
+$d=(q^2L/2\pi\vareplison_0mg)^{1/3}$.  (Hint: If $\theta$ is small,
+then $\tan\theta\approx\sin\theta$.)
+\end{problem*}
+
+\begin{solution}
+\end{solution}
diff --git a/latex/problems/Young_and_Freedman_12/problem21.76.tex b/latex/problems/Young_and_Freedman_12/problem21.76.tex
new file mode 100644
index 0000000..9a42442
--- /dev/null
+++ b/latex/problems/Young_and_Freedman_12/problem21.76.tex
@@ -0,0 +1,24 @@
+\begin{problem*}{76}
+Two identical spheres are each attached to silk threads of length
+$L=0.500\U{m}$ and hung from a common point (Fig.~21.44).  Each sphere
+has a mass $m=8.00\U{g}$.  The radius of each sphere is very small
+compared to the distance between the spheres, so they may be treated
+as point charges.  One sphere is given positive charge $q_1$, and the
+other a diferent positive charge $q_2$; this causes the spheres to
+separate so that when the spheres are in equilibrium, each thread
+makes an angle $\theta=20.0\dg$ with the vertical.  \Part{a} Draw a
+free-body diagram for each sphere when in equlibrium, and label all
+the forces that act on each sphere.  \Part{b} Determine the magnitude
+of the electrostatic force that eacts on each sphere, and determine
+the tension in each thread.  \Part{c} Based on the information you
+have been given, what can you say about the magnitudes of $q_1$ and
+$q_2$?  Explain your answers.  \Part{d} A small wire is now connected
+between the spheres, allowing charge to be transferred from one sphere
+to the other until the two spheres have equal charges; the wire is
+then removed.  Each thread now makes an angle of $30.0\dg$ with the
+vertical.  Determine the original charges.  (Hint: The total charge on
+the pair of spheres is conserved).
+\end{problem*}
+
+\begin{solution}
+\end{solution}
diff --git a/latex/problems/Young_and_Freedman_12/problem21.81.tex b/latex/problems/Young_and_Freedman_12/problem21.81.tex
new file mode 100644
index 0000000..1e992ae
--- /dev/null
+++ b/latex/problems/Young_and_Freedman_12/problem21.81.tex
@@ -0,0 +1,11 @@
+\begin{problem*}{81}
+Imagine two $1.0\U{g}$ bags of protons, one at the earth's north pole
+and the other at the south pole.  \Part{a} How many protons are in
+each bag?  \Part{b} Calculate the gravitational attraction and the
+electrical repulsion that each bag exerts on the other.  \Part{c} Atre
+the forces in \Part{b} large enough for you to feel if you were
+holding one of the bags?
+\end{problem*}
+
+\begin{solution}
+\end{solution}
diff --git a/latex/problems/Young_and_Freedman_12/problem22.16.tex b/latex/problems/Young_and_Freedman_12/problem22.16.tex
new file mode 100644
index 0000000..d0a64b9
--- /dev/null
+++ b/latex/problems/Young_and_Freedman_12/problem22.16.tex
@@ -0,0 +1,9 @@
+\begin{problem*}{16}
+A solid metal sphere with radius $0.450\U{m}$ carries a net charge of
+$0.250\U{nC}$.  Find the magnitude of the electric field \Part{a} at a
+point $0.100\U{m}$ outside the surface of the sphere and \Part{b} at a
+point inside the sphere, $0.100\U{m}$ below the surface.
+\end{problem*}
+
+\begin{solution}
+\end{solution}
diff --git a/latex/problems/Young_and_Freedman_12/problem22.18.tex b/latex/problems/Young_and_Freedman_12/problem22.18.tex
new file mode 100644
index 0000000..88df491
--- /dev/null
+++ b/latex/problems/Young_and_Freedman_12/problem22.18.tex
@@ -0,0 +1,13 @@
+\begin{problem*}{18}
+Some planetary scientists have suggested that the planet Mars has an
+electric field somewhat similar to that of the earth, producing a net
+electric flux of $3.63\E{16}\U{N$\cdot$m$^2$/C}$ at the planet's
+surface.  Calculate: \Part{a} the total electric charge on the
+planet; \Part{b} the electric field at the planet's surface (refer to
+the astronomical data inside the back cover); \Part{c} the charge
+density on Mars, assuming all the charge is uniformly distributed over
+the planet's surface.
+\end{problem*}
+
+\begin{solution}
+\end{solution}
diff --git a/latex/problems/Young_and_Freedman_12/problem22.23.tex b/latex/problems/Young_and_Freedman_12/problem22.23.tex
new file mode 100644
index 0000000..e42e132
--- /dev/null
+++ b/latex/problems/Young_and_Freedman_12/problem22.23.tex
@@ -0,0 +1,13 @@
+\begin{problem*}{23}
+A hollow, conducting sphere with an outer radius of $0.250\U{m}$ and
+an inner radius of $0.200\U{m}$ has a uniform surface charge density
+of $+6.37\E{-6}\U{C/m$^2$}$.  A charge of $-0.500\U{$\mu$C}$ is now
+introduced into the cavity inside the sphere.  \Part{a} What is the
+new charge density on the outsize of the sphere?  \Part{b} Calculate
+the strength of the electric field just outside the sphere.  \Part{c}
+What is the electric flux through the spherical surface just inside
+the inner surface of the sphere?
+\end{problem*}
+
+\begin{solution}
+\end{solution}
diff --git a/latex/problems/Young_and_Freedman_12/problem22.25.tex b/latex/problems/Young_and_Freedman_12/problem22.25.tex
new file mode 100644
index 0000000..4b85589
--- /dev/null
+++ b/latex/problems/Young_and_Freedman_12/problem22.25.tex
@@ -0,0 +1,11 @@
+\begin{problem*}{25}
+The electric field at a distance of $0.145\U{m}$ from the surface of a
+solid insulating sphere with a radius $0.355\U{m}$ is
+$1750\U{N/C}$.  \Part{a} Assuming the sphere's charge is uniformly
+distributed, what is the charge density inside it?  \Part{b} Calculate
+the electric field inside the sphere at a distance of $0.200\U{m}$
+from the center.
+\end{problem*}
+
+\begin{solution}
+\end{solution}
diff --git a/latex/problems/Young_and_Freedman_12/problem22.37.tex b/latex/problems/Young_and_Freedman_12/problem22.37.tex
new file mode 100644
index 0000000..b12c0a5
--- /dev/null
+++ b/latex/problems/Young_and_Freedman_12/problem22.37.tex
@@ -0,0 +1,16 @@
+\begin{problem*}{37}
+A long coaxial cable consists of an inner cylindrical conductor with a
+radius $a$ and an outer coaxial cylinder with inner radius $b$ and
+outer radius $c$.  The outer cylinder is mounted on insulating
+supports and has no net charge.  The inner cylinder has a uniform
+positive charge per unit length $\lambda$.  Caluculate the electric
+field \Part{a} at any point between the cylinders a distance $r$ from
+the axis and \Part{b} at any point outside the cylinder.  \Part{c}
+Graph the magnitude of the electric field as a function of the
+distance $r$ from the axis of the cable, from $r=0$ to
+$r=2c$.  \Part{d} Find the charge per unit length on the inner surface
+and on the outer surface of the outer cylinder.
+\end{problem*}
+
+\begin{solution}
+\end{solution}
diff --git a/latex/rec/rec1/all_problems.tex b/latex/rec/rec1/all_problems.tex
index f314bd4..2902a1f 100644
--- a/latex/rec/rec1/all_problems.tex
+++ b/latex/rec/rec1/all_problems.tex
@@ -1,7 +1,7 @@
 \usepackage[author={W. Trevor King},
-            coursetitle={Physics 201},
-            classtitle={Recitation 1},
-            subheading={Chapter 12}]{problempack}
+            coursetitle={Physics 102},
+            classtitle={Recitation Week 1},
+            subheading={Chapter 21}]{problempack}
 \usepackage[inline]{asymptote}
 \usepackage{wtk_cmmds}
 
@@ -14,5 +14,8 @@
 \input{problem3}
 \input{problem4}
 \input{problem5}
+\input{problem6}
+\input{problem7}
+\input{problem8}
 
 \end{document}
diff --git a/latex/rec/rec1/problem1.tex b/latex/rec/rec1/problem1.tex
index 9d042e9..66a51bc 120000
--- a/latex/rec/rec1/problem1.tex
+++ b/latex/rec/rec1/problem1.tex
@@ -1 +1 @@
-../../problems/problem12.02.tex
\ No newline at end of file
+../../problems/Young_and_Freedman_12/problem21.34.tex
\ No newline at end of file
diff --git a/latex/rec/rec1/problem2.tex b/latex/rec/rec1/problem2.tex
index fad3569..d4ba5f3 120000
--- a/latex/rec/rec1/problem2.tex
+++ b/latex/rec/rec1/problem2.tex
@@ -1 +1 @@
-../../problems/problem12.05.tex
\ No newline at end of file
+../../problems/Young_and_Freedman_12/problem21.47.tex
\ No newline at end of file
diff --git a/latex/rec/rec1/problem3.tex b/latex/rec/rec1/problem3.tex
index 9ad2afd..7c26167 120000
--- a/latex/rec/rec1/problem3.tex
+++ b/latex/rec/rec1/problem3.tex
@@ -1 +1 @@
-../../problems/problem12.12.tex
\ No newline at end of file
+../../problems/Young_and_Freedman_12/problem21.72.tex
\ No newline at end of file
diff --git a/latex/rec/rec1/problem4.tex b/latex/rec/rec1/problem4.tex
index 1964d5c..27e8cd3 120000
--- a/latex/rec/rec1/problem4.tex
+++ b/latex/rec/rec1/problem4.tex
@@ -1 +1 @@
-../../problems/problem12.15.tex
\ No newline at end of file
+../../problems/Young_and_Freedman_12/problem21.74.tex
\ No newline at end of file
diff --git a/latex/rec/rec1/problem5.tex b/latex/rec/rec1/problem5.tex
index 64a05d8..fbf5391 120000
--- a/latex/rec/rec1/problem5.tex
+++ b/latex/rec/rec1/problem5.tex
@@ -1 +1 @@
-../../problems/problem12.18.tex
\ No newline at end of file
+../../problems/Young_and_Freedman_12/problem21.76.tex
\ No newline at end of file
diff --git a/latex/rec/rec1/problem6.tex b/latex/rec/rec1/problem6.tex
new file mode 120000
index 0000000..31944ae
--- /dev/null
+++ b/latex/rec/rec1/problem6.tex
@@ -0,0 +1 @@
+../../problems/Young_and_Freedman_12/problem21.81.tex
\ No newline at end of file
diff --git a/latex/rec/rec1/problem7.tex b/latex/rec/rec1/problem7.tex
new file mode 120000
index 0000000..bbb19af
--- /dev/null
+++ b/latex/rec/rec1/problem7.tex
@@ -0,0 +1 @@
+../../problems/Young_and_Freedman_12/problem21.84.tex
\ No newline at end of file
diff --git a/latex/rec/rec1/problem8.tex b/latex/rec/rec1/problem8.tex
new file mode 120000
index 0000000..216aad6
--- /dev/null
+++ b/latex/rec/rec1/problem8.tex
@@ -0,0 +1 @@
+../../problems/Young_and_Freedman_12/problem21.86.tex
\ No newline at end of file
-- 
2.26.2