Momentum = (mass) x (speed)
Change in momentum = (force) x (time)
The initial momentum is (mass) x (speed) = 2500x 25 = 62,500 kg-m/s.
Since you want to stop the vehicle, that number is also the required change
in momentum ... you want the vehicle to wind up with zero momentum.
62,500 = (force) x (time) = 20 x force
Divide each side by 20 :
force = 62,500 / 20 = 3,125 newtons
