Choose the one alternative that best completes the statement or answers the question.
-The distance it takes to stop a car varies directly as the square of the speed of the car. If it takes 112 feet for a car traveling at 40 miles per hour to stop, what distance is required for a speed of 58 miles per hour?
A) $247.78 \mathrm{ft}$
B) $235.48 \mathrm{ft}$
C) $201.84 \mathrm{ft}$
D) $235.82 \mathrm{ft}$

Question

Quizplus · Accepted Answer

The stopping distance $d$ is proportional to the square of the speed $s$, so $d = k \cdot s^2$. Given $d = 112$ ft at $s = 40$ mph, we find $k = \frac{112}{40^2}$. For $s = 58$ mph, $d = k \cdot 58^2$, which calculates to approximately 235.48 ft.

Choose the One Alternative That Best Completes the Statement or Answers