Question

F mb = 1.0 kg, how large must ma be if the acceleration of the system is to be kept at g100

Answer 1

From (1): 
(mA + mB) (a / g) = mB 
mA (a / g) = mB (1 - a / g) 
mA = mB (g / a - 1) 
mA = 1.0 (100 - 1) 
mA = 99 kg.

99 kg must be the mA be if the acceleration of the system is to be kept at g100.