Answer: 36.22 feet
Explanation:
Two quantities are proportional if and only if their ratio is constant. Since V and the square of R are proportional, then the ratio of V to the square of R is constant. In terms of equation:
[tex] \frac{V}{R^2} = k[/tex]
For some constant k.
Since the constant of proportionality is equal to 0.1639, k = 0.1639. Moreover, since the takeoff speed of the aircraft needs to be 215 miles per hour, the runway needed is will be obtained by solving for R in the following equation:
[tex]\frac{V}{R^2} = k
\\
\\ V = kR^2
\\
\\ R^2 = \frac{V}{k}
\\
\\ R = \sqrt{\frac{V}{k}}
\\
\\ R = \sqrt{\frac{215}{0.1639}}
\\
\\ \boxed{R = 36.22 \text{ feet}}
[/tex]
Hence, a runway of 36.22 feet is needed for the aircraft to have a takeoff speed of 215 miles per hour.