\magnification=\magstep1


$$
\eqalign{
{\rm Period\ \ } P \quad &= \quad  {{2 \pi R} \over {v}}  \cr
                         &\phantom{=} \cr
                         &= \quad  0.005 \thinspace s  \cr
}
$$

$$
{\rm strain\ \ } h \quad \sim \quad {{G M}\over{c^2}} \ \ {{1}\over{D}} \ \ 
                                { \left( {{v}\over{c}} \right)^2 }
$$


$$
{\rm length\ change\ } \Delta x \quad = \quad h \thinspace L
$$

\bye
