deletions | additions       diff --git a/The Moon.tex b/The Moon.tex  index d14af67..5ba3167 100644  --- a/The Moon.tex  +++ b/The Moon.tex 
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F_{\rm grav} = \frac{G M_\oplus M_{\rm moon}}{a_m^2} = M_{\rm moon} \dot{V}_m  \end{equation}  Where $\dot{V}_m = V_m^2/a_m$ is the centripetal acceleration of the Moon due to its (nearly) circular orbit.     \begin{align}   \frac{G M_\oplus}{a_m^2} = {V_m^2/a_m}   \end{align}     The Moon travels a distance $2\pi a_m$ every period, so $V_m = 2\pi a_m / P_m$     \begin{align}   \frac{G M_\oplus}{a_m^2} = \frac{4\pi^2 a_m^2}{P_m a_m}   \end{align}  \item {\it What is the Moon's radius?}  \item {\it What is the Moon's mass?}  \end{enumerate}