Understanding the Concepts

* Acceleration: The rate at which an object's velocity changes over time.

* Formula: Acceleration (a) = (Change in velocity (Δv)) / (Time (Δt))

Applying the Formula

1. Change in velocity (Δv): You provided this as 9 m/s.

2. Time (Δt): You provided this as 4 seconds.

Calculation

* a = (9 m/s) / (4 s)

* a = 2.25 m/s²

Answer: The acceleration of the car is 2.25 meters per second squared.