Bert & Ernie are running a race; when the starting pistol fires, Bert sprints forward with a constant speed of 7 m.s; Ernie is still tying his shoes when the pistol fires and begins running 6 seconds after Bert and accelerates at a rate of 3 m/s2 for 4 seconds then continues running at a constant velocity. Determine at what time and displacement Ernie catches Bert.