# Question #5f7c5

Jan 4, 2017

The distance $= 800 m$

#### Explanation:

We use the equation

${v}^{2} = {u}^{2} + 2 a s$

The initial velocity is $u = 80 m {s}^{-} 1$

The final velocity is $v = 0$ (the racecar stopped)

The acceleration is $a = - 4 m {s}^{-} 2$

The distance is $s = - {u}^{2} / \left(2 a\right) = - {80}^{2} / \left(2 \cdot \left(- 4\right)\right)$

$= 80 \cdot \frac{80}{8} = 800 m$