Understanding the Concepts

* Acceleration: Acceleration is the rate of change of velocity over time.

* Initial Velocity (vi): The starting velocity of the vehicle (70 m/s).

* Final Velocity (vf): The ending velocity of the vehicle (0 m/s since it comes to a stop).

* Time (t): The time it takes to change velocity (35 s).

Formula

The formula for acceleration is:

acceleration (a) = (final velocity (vf) - initial velocity (vi)) / time (t)

Calculation

1. Plug in the values:

a = (0 m/s - 70 m/s) / 35 s

2. Solve the equation:

a = -70 m/s / 35 s

a = -2 m/s²

Answer:

The acceleration of the vehicle is -2 m/s². The negative sign indicates that the vehicle is decelerating (slowing down).