Answer
The maximum possible acceleration of the truck is $1.8~m/s^2$
Work Step by Step
The tension force $F_T$ in the rope can accelerate the car forward. We can find the maximum possible acceleration of the car:
$ma = F_T$
$a = \frac{F_T}{m}$
$a = \frac{2500~N}{1400~kg}$
$a = 1.8~m/s^2$
Since the car and truck are tied together, the maximum possible acceleration of the truck is $1.8~m/s^2$
