\magnification=\magstep2

$$
{\rm KE\ } \quad = \quad {{1}\over{2}} m v^2
$$

$$
{\rm 1\ Joule\ } \quad = \quad {1} \thinspace\thinspace {{ \rm kg\ m^2} \over {{\rm s^2}} }
$$

$$
\eqalign{
{v_{1}} \quad &= \quad \left ( {{m_1 - m_2} \over {m_1 + m_2} } \right ) v \cr
\cr
{v_{2}} \quad &= \quad \left ( {{2 m_1} \over {m_1 + m_2} } \right ) v \cr
}
$$

$$
{\rm STI \ } \quad = \quad \sqrt{ {(c \Delta t)}^2 - {( \Delta x)}^2 }
$$


\bye
