From e60f485c89e50d178458a69ad9e66030fe3658e1 Mon Sep 17 00:00:00 2001
From: "W. Trevor King" <wking@tremily.us>
Date: Fri, 20 Apr 2012 17:08:29 -0400
Subject: [PATCH] Add question text and figures for Serway and Jewett v8's
 25.7, .12, and .16.

---
 .../Serway_and_Jewett_8/problem25.07.tex      | 33 +++++++++++++++++++
 .../Serway_and_Jewett_8/problem25.12.tex      | 21 ++++++++++++
 .../Serway_and_Jewett_8/problem25.16.tex      | 20 +++++++++++
 3 files changed, 74 insertions(+)

diff --git a/latex/problems/Serway_and_Jewett_8/problem25.07.tex b/latex/problems/Serway_and_Jewett_8/problem25.07.tex
index 083adda..238876f 100644
--- a/latex/problems/Serway_and_Jewett_8/problem25.07.tex
+++ b/latex/problems/Serway_and_Jewett_8/problem25.07.tex
@@ -1,4 +1,37 @@
 \begin{problem*}{25.7}
+A particle having charge $q=+2.00\U{$\mu$C}$ and mass $m=0.0100\U{kg}$
+is connected to a string that is $L=1.50\U{m}$ long and tied to the
+pivot point $P$ in Figure~P25.7.  The particle, string, and the pivot
+point all lie on a frictionless, horizontal table.  The particle is
+released from rest when the string makes an angle $\theta=60.0\dg$
+with a uniform electric field of magnitude $E=300\U{V/m}$.  Determine
+the speed of the particle when the string is parallel to the electric
+field.
+\begin{center}
+\begin{asy}
+import Mechanics;
+import ElectroMag;
+
+real u = 3cm;
+real theta = 60;
+pair a = u*dir(theta);
+pair b = (u, 0);
+
+Angle t = Angle(a, (0,0), b, "$\theta$");  t.draw();
+draw(a -- (0,0) -- b);
+dot("$P$", (0,0), align=W);
+Charge A = pCharge(a, Label("$m$", align=N));  A.draw();
+A.lc.draw_label(Label("$q$", align=E));
+A.lc.draw_label(Label("$v=0$", align=W));
+label("$L$", a/2, align=NW);
+
+Vector v = Velocity(b, mag=u/3, dir=-90, "$\vect{v}$");  v.draw();
+Charge B = pCharge(b);  B.draw();
+Vector E = EField((0.7u,u/2), mag=u/3, "$\vect{E}$");  E.draw();
+
+label("Top view", (u/2, 0), align=S);
+\end{asy}
+\end{center}
 \end{problem*}
 
 \begin{solution}
diff --git a/latex/problems/Serway_and_Jewett_8/problem25.12.tex b/latex/problems/Serway_and_Jewett_8/problem25.12.tex
index 46f1c3c..b3a8dc2 100644
--- a/latex/problems/Serway_and_Jewett_8/problem25.12.tex
+++ b/latex/problems/Serway_and_Jewett_8/problem25.12.tex
@@ -1,4 +1,25 @@
 \begin{problem*}{25.12}
+The two charges in Figure~P25.12 are separated by $d=2.00\U{cm}$.
+Find the electic potential at \Part{a} point $A$ and \Part{b} point
+$B$, which is halfway between the charges.
+\begin{center}
+\begin{asy}
+import Mechanics;
+import ElectroMag;
+
+real u = 3cm;
+
+pair A = (u/2,sqrt(3)/2*u);
+draw((0,0) -- A -- (u,0) -- cycle);
+dot("$A$", A, align=N);
+dot("$B$", (u/2,0), align=N);
+Charge a = nCharge((0,0), Label("$-15.0\U{nC}$", align=S));  a.draw();
+Charge b = pCharge((u,0), Label("$27.0\U{nC}$", align=S));  b.draw();
+label("$d$", A/2, align=NW);
+label("$d$", A/2 + (u/2,0), align=NE);
+label("$d$", (u/2, 0), align=S);
+\end{asy}
+\end{center}
 \end{problem*}
 
 \begin{solution}
diff --git a/latex/problems/Serway_and_Jewett_8/problem25.16.tex b/latex/problems/Serway_and_Jewett_8/problem25.16.tex
index d7d0202..bdf7ea8 100644
--- a/latex/problems/Serway_and_Jewett_8/problem25.16.tex
+++ b/latex/problems/Serway_and_Jewett_8/problem25.16.tex
@@ -1,4 +1,24 @@
 \begin{problem*}{25.16}
+The two charges in Figure~P25.16 are separated by a distance
+$d=2.00\U{cm}$, and $Q=+5.00\U{nC}$.  Find \Part{a} the electric
+potential at $A$, \Part{b} the electric potential at $B$, and \Part{c}
+the electric potential difference between $B$ and $A$.
+\begin{center}
+\begin{asy}
+import Mechanics;
+import ElectroMag;
+
+real u = 2cm;
+
+draw(scale(u)*unitsquare, dashed);
+dot("$A$", (0,u), align=N);
+dot("$B$", (u,u), align=N);
+Charge a = pCharge((u,0), Label("$2Q$", align=S));  a.draw();
+Charge b = pCharge((0,0), Label("$Q$", align=S));  b.draw();
+label("$d$", (0, u/2), align=W);
+label("$d$", (u/2, 0), align=S);
+\end{asy}
+\end{center}
 \end{problem*}
 
 \begin{solution}
-- 
2.26.2