Final answer:
The average speed during braking can be calculated by finding the change in velocity and dividing it by the time taken to stop. In this case, the average speed during braking is 5.4 m/s.
Step-by-step explanation:
The average speed during braking can be determined by dividing the change in velocity by the time taken. In this case, the initial speed is 27 m/s and the final speed is 0 m/s since the car comes to a stop. To calculate the average speed during braking, we need to calculate the change in velocity and divide it by the time taken to stop. Let's assume the time taken to stop is 5 seconds.
The change in velocity is calculated by subtracting the final speed from the initial speed: 0 m/s - 27 m/s = -27 m/s. Since velocity is a vector quantity, the negative sign indicates a change in direction.
Therefore, the average speed during braking is |-27 m/s / 5 s| = 5.4 m/s.