ok i have a physics question.?

Question

a car is moving at a constant speed of 14m/s when the driver presses down the pedal for 11 seconds at an acceleration of 1.6m/s2. what is the average speed of the car???

Answer 1

31.6m/s

Answer 2

With an initial constant speed of 14m/s and an deacceleration of 1.6m/s2, it takes 14/1.6 = 8.75(s) to stop the car.
From the time the driver presses down the pedal, to finally the car stops, the car should have moved:
0.5*14*8.75 = 61.25 (m)
So the average speed of the car is: 61.25/11 = 5.6 (m/s)