Final answer:
The car's acceleration is calculated by subtracting the initial velocity from the final velocity and then dividing by the time taken, yielding approximately 1.71 m/s², or 2 m/s² when rounded.
Step-by-step explanation:
The acceleration of a car can be calculated using the formula acceleration (a) = (final velocity (v) - initial velocity (u)) / time (t). In this case, the car goes from 18 m/s to 30 m/s in 7 seconds. Using the formula:
a = (v - u) / t
a = (30 m/s - 18 m/s) / 7 s
a = 12 m/s / 7 s
a = 1.71 m/s²
Rounding to the nearest whole number, the correct answer is 2 m/s², which corresponds to option B.