Question

1. the distance d in feet that it takes a car to stop if it is traveling s miles per hour is given by ( s = sqrt{21d} ). find the distance it would take a car traveling 60 miles per hour to stop. round your answer to the nearest tenth of a foot.

Explanation:

Step1: Identify the formula and given value

We are given the formula \( S = \sqrt{21d} \), and \( S = 60 \) miles per hour. We need to solve for \( d \).

Step2: Square both sides of the equation

To eliminate the square root, square both sides: \( S^2 = 21d \). Substitute \( S = 60 \): \( 60^2 = 21d \).

Step3: Calculate \( 60^2 \)

\( 60^2 = 3600 \), so the equation becomes \( 3600 = 21d \).

Step4: Solve for \( d \)

Divide both sides by 21: \( d=\frac{3600}{21}\approx171.4 \) (rounded to the nearest tenth).

Answer:

\( 171.4 \)