Understanding the Concepts
* Initial Velocity (v₀): The car's starting speed (19 m/s).
* Final Velocity (v): The car comes to a stop, so its final velocity is 0 m/s.
* Stopping Distance (Δx): The distance the car travels while braking (31 meters).
* Acceleration (a): The rate at which the car slows down (this is what we need to find).
Equation to Use
We can use the following kinematic equation:
v² = v₀² + 2aΔx
Solving for Acceleration
1. Rearrange the equation:
a = (v² - v₀²) / (2Δx)
2. Plug in the values:
a = (0² - 19²) / (2 * 31)
3. Calculate:
a = (-361) / (62)
a ≈ -5.82 m/s²
Important Note: The negative sign indicates that the acceleration is in the opposite direction to the car's initial motion. This means the car is decelerating or slowing down.
Answer: The magnitude of the car's acceleration is approximately 5.82 m/s².