Solve the Problem $= \sqrt { 30 f d }$ To Estimate the Speed S of a Car in Miles

Multiple Choice

Solve the problem.
-Police use the formula s $= \sqrt { 30 f d }$ to estimate the speed s of a car in miles per hour, where $d$ is the distance in feet that the car skidded and $\mathrm { f }$ is the coefficient of friction. If the coefficient of friction on a certain dry road is $0.84$ and a car was traveling on it at a rate of $40 \mathrm { mph }$ , how far will the car skid? Round to the nearest foot.

A) $32 \mathrm { ft }$
B) $53 \mathrm { ft }$
C) $403 \mathrm { ft }$
D) $63 \mathrm { ft }$