An automobile manufacturer claims that its product will, starting from rest, travel 0.40 km in 9.0 s. What is the magnitude of the constant acceleration required to do this? A) 9.9 m/s² B) 8.9 m/s² C) 6.6 m/s² D) 5.6 m/s² E) 4.6 m/s²

Question

Quizplus · Accepted Answer

The distance traveled under constant acceleration from rest is given by the formula $d = \frac{1}{2}at^2$, where $d$ is the distance, $a$ is the acceleration, and $t$ is the time. Rearranging for $a$, we get $a = \frac{2d}{t^2}$. Substituting $d = 0.40 \, km = 400 \, m$ and $t = 9.0 \, s$, we find $a = \frac{2 \times 400}{9.0^2} = \frac{800}{81} \approx 9.9 \, m/s^2$.

An Automobile Manufacturer Claims That Its Product Will, Starting from Rest