what is the maximum speed a car could be traveling in order to stop within 40ft?

Question

d=0.05V^2+1.20V

Answer 1

take a look at the graph:

.05v^2+1.20v <= 40

http://www.wolframalpha.com/input/?i=1.20v%2B.05v^2+%3C%3D+40

Though I don't see how the car will come to a stop.