3. A driver who is moving at 15 m/s, sees a stop light and puts on the brakes 30 m before an intersection. a) What acceleration will the driver have to have to stop before entering the intersection? The intial speed is u = 15 m/s The distance is s = 30 m The final velocity is v = 0 v2=u2+2 as 0 = (15 m/s)+2ax 30 m a=-(15 m/s)2/2 x 30m a = -3.75 m/s2 -3.75 m/s