Originally Posted By: paul

its final velocity is 52.193 m/s
its braking force is 5219.3 N


That force is chosen arbitrarily. It need not be 5219.3N. And in fact it cannot be now that you demand <<2s turnaround.

a=F/m
a = 5219.3N / 100kg
a = 52.2 m/s^2
At that acceleration/deceleration, how much time do you think it'll take to stop or turn around?

You must specify a higher braking force.