3. A small car travels along a straight road in one direction. It starts with an initial speed of v; = 63 km/h and slows down to vy = 2m/s in 120m. Assuming the rate of change of velocity is constant, (a) (1.5 marks) compute the acceleration of the car, and (b) (1.5 marks) calculate the time it takes to slow down from vi to uf. Draw appropriate diagrams and axes, and think about directions of vector quantities