Final answer:
The commuter's car decelerates at a rate of -2.50 m/s² when she brakes to a stop over a period of 0.800 seconds, indicating a constant deceleration.
Step-by-step explanation:
Deceleration Calculation
To determine the commuter's car deceleration, we will use the formula for constant acceleration, which is:
a = Δv / Δt
where a is the acceleration, Δv is the change in velocity, and Δt is the change in time. Braking to a stop means the final velocity (vf) is 0 m/s. We know the initial velocity (vi) is 2.00 m/s and the time (t) to stop is 0.800 s. Inserting these values into the formula gives us:
a = (0 m/s - 2.00 m/s) / 0.800 s
a = -2.00 m/s / 0.800 s
a = -2.50 m/s²
The negative sign indicates that this is a deceleration, or negative acceleration, because the car is slowing down.