A car traveling at 46 mph decelerates at 21 feet per second per second.

a). How long does it take for the car to come to a complete stop?
b). What distance is required to bring the car to a complete stop? An

3 answers

convert 46 mph to ft/s. If that value is c, then

v = c-21t
solve for t when v=0

the distance s is

s = ct - 10.5 t^2
-51.6
5t