\documentclass[10pt]{article}
\pagestyle{empty}

\parindent=0pt
\parskip=.1in

\newcommand\hs{\hspace{6pt}}

\begin{document}

\centerline{\textbf{Work in Thermodynamic Systems}}
\bigskip

  What \textbf{work} is can depend on the system you are looking at.
  \begin{itemize}
  \item For a 3-D thing, $-pdV$
  \item For a 2-D thing, $\sigma dA$
  \item For a 1-D thing, $\tau dL$
  \item For a dielectric material, $-\vec{E}\cdot d\vec{P}$, for a
    paramagnet $-\vec{B}\cdot d\vec{M}$ etc...
  \end{itemize}

\medskip

  With this in mind, determine if in the following scenarios work is either done \emph{by} or \emph{on} the system (i.e. does the system lose or gain energy by working?).
  \begin{enumerate}
  \item A gas in a piston that is being compressed.  \textit{Does it matter if
    it's a liquid instead?}
  \item A balloon in a box (of vacuum) that is popped.  \textit{What if the
    air is the system? What if the balloon \& the air together form
    the system?}
  \item A gas in a piston that is expanded.
  \item Ice in a piston that is being compressed.
  \item A rubber band that is being stretched.
  \item A soap bubble that is being blown.
  \item A piece of iron that is being magnetized.
  \item A rubber band that is snapped shut in a vacuum.
  \end{enumerate}
  
\vfill
\leftline{\textit{by David Roundy}}
\leftline{\copyright DATE David Roundy}
\end{document}