Answer:

The car's acceleration can be determined using the formula:

acceleration = change in velocity / time

where change in velocity is the difference between the final velocity (20 m/s) and the initial velocity (0 m/s), and time is the time taken to achieve this change in velocity (3 seconds).

So, the acceleration of the car is:

acceleration = (20 m/s - 0 m/s) / 3 s

acceleration = 6.67 m/s^2

Therefore, the car's acceleration is 6.67 m/s^2.