Mingled in among all those words, this question is just another
application of Newton's 2nd law of motion.
Force = (mass) x (acceleration)
Acceleration = (change in speed) / (time for the change)
Acceleration = (45 m/s) / (7 sec) = (45/7) m/s²
Force = (5,600 kg) x (45/7 m/s²)
Force = (800 x 45) Newtons
Force = 36,000 Newtons