Answer
a). The direction of the acceleration vector is opposite to velocity vector because the car is decelerating, which has opposite direction as that of acceleration.
b). So, change in velocity in each second = 2.2 m/s.
Work Step by Step
a). The direction of the acceleration vector is opposite to velocity vector because the car is decelerating, which has opposite direction as that of acceleration.
b). $40 km/hr = 40\times \frac{1000m}{3600 s}=11.11 m/s$
Acceleration = $-\frac{11.11}{5}=-2.2m/s^{2}$
So, change in velocity in each second = 2.2 m/s.