Answer:
The car took 2.5 seconds for this acceleration
Step-by-step explanation:
Constant Acceleration Motion
It's a type of motion in which the velocity of an object changes by an equal amount in every equal period of time.
Being a the constant acceleration, vo the initial speed, vf the final speed, and t the time, the following relation applies:

Solving for t:

The car was traveling at v0=7 m/s, accelerated at 2.5 m/s^2, and reached a speed vf=12 m/s. Calculating the time taken:


t=2 sec
The car took 2 seconds for this acceleration