Answer
$a=24.23m/s^2$
Work Step by Step
We can determine the required acceleration as follows:
We know that:
$F_D=m\frac{dv}{dt}-v_{D/e}\frac{dm_e}{dt}+v_{D/i}\frac{dm_i}{dt}$
$55v_{D/i}^2=ma-v_{D/e}\frac{dm_e}{dt}+v_{D/i}\frac{dm_i}{dt}$
We plug in the known values to obtain:
$55(200)^2=7000a-(12000)(200+0.8)+(200)(200)$
This simplifies to:
$a=24.23m/s^2$
