I used the right environment + commands but I don't understand why my "1." the top of the diagram and the first line of the equation don't line up. Whatever else follows doesn't have to be aligned but those three things should align properly.
\documentclass[fleqn]{article}
\usepackage{fullpage}
\usepackage[left=1in,right=1in,top=1in,bottom=1in]{geometry}
\usepackage{graphicx}
\usepackage{wrapfig}
\usepackage{amsmath}
\usepackage[makeroom]{cancel}
\pagestyle{empty}
\begin{document}
\begin{enumerate}
\item
\includegraphics{Diagram.pdf}
\begin{minipage}[t]{2in}
$\begin{aligned}[t]
v&=\cfrac{2\pi d}{T} \\
v&=\cfrac{2\pi r\cos\theta}{T} \\
v&=\cfrac{2\pi(\text{6.37\e{6} m})\cos\text{(40.1)}}{\text{86,400 s}} \\
v&=\text{354.34 m/s} \\
\end{aligned}$
\end{minipage}
\end{enumerate}
\end{document}
\e
. But I have a feeling that this question might be related to this question about alignment of item number in list containing a minipage