Final answer:
The average velocity of the car during its braking period is 12 m/s.
Step-by-step explanation:
To find the average velocity of the car during its braking period, we need to consider the total displacement over the time taken to stop. Since the car decelerates uniformly from 24 m/s to rest and travels a distance of 48 m, the average velocity can be calculated by dividing the total displacement by the time taken to stop. The formula for average velocity (vavg) when starting with an initial velocity (vi) and ending with a final velocity (vf) is: vavg = (vi + vf)/2. In this case, the initial velocity is 24 m/s, and the final velocity is 0 m/s, as the car comes to a rest. Therefore, the average velocity of the car during braking is: vavg = (24 m/s + 0 m/s)/2 = 12 m/s.