A 0.17 kg baseball moving at +20.80 m/s is slowed to a stop by a catcher who exerts a constant force of -357 N.
How long does it take this force to stop the ball?
How far does the ball travel before stopping?
a = F/m = 357/0.17
v = 20.80 - at
solve for t when v=0
Then use that to find
s = 20.80t - 1/2 at^2