$($adopted from Wiesel, p$.39)$ A reentry vehicle is flying through

the atmosphere at velocity vec$(V)=$Vhat$(b{)}_1$ with flight$-$path angle $$

$($gamma$)$ as shown in the figure. The vehicle keeps its velocity

aligned with hat$(b{)}_1$ as $$ changes. Show that the inertial acceleration

of the center of mass can be written as

vec$(A)=V^{}$hat$(b{)}_1+V{}^{}$hat$(b{)}_2$

DETERMINE THE ACCELERATION OF THE MASS M WRT THE INTERTIAL FRAME