I really don't know how to find the acceleration at the intersection. You are driving to the grocery store at 19 m/s. You are 140 m from an intersection when the traffic light turns red. Assume that your reaction time is 0.77 s and that your car brakes with constant acceleration. I have found that d1=130m I tried to find the acceleration and I got 25, but it's wrong. Could someone help me with this problem?