A motorist is traveling at 18 m/s^2 when he sees a deer 38 m ahead. If the maximum negative acceleration is -4.5 m/s^2, what is the reaction time (delta t) of the motorist that will allow him to avoid hitting the deer? Answer in units of 's'. I tried using x(t)=x0+v0t+1/2at^2 and it didn't work out for me. I know the answer is supposed to be 0.1111 s and I can't get this no matter what I try. help!