Final answer:
The car's acceleration as it slows to a stop is -3 m/s², indicating it is decelerating.
Step-by-step explanation:
A car slows to a stop from a speed of 15 m/s in 5.0 s. To find the car's acceleration, you can use the formula a = (vf - vi) / t, where 'a' is acceleration, 'vf' is final velocity, 'vi' is initial velocity, and 't' is time. Since the car comes to a stop, the final velocity (vf) is 0 m/s, and the initial velocity (vi) is 15 m/s. The time (t) taken to stop is 5.0 s.
Plugging in the values, we get a = (0 m/s - 15 m/s) / 5.0 s = -15 m/s / 5.0 s = -3 m/s². The negative sign indicates that the acceleration is in the opposite direction of the initial motion, which is expected since the car is slowing down.