Solve the Problem $s = \sqrt { 30 f d }$

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 $\mathrm { d }$ 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 $0.86$ and a car was traveling on it at a rate of $60 \mathrm { mph }$ , how far will the car skid? (Round to the nearest foot.)

A) $929 \mathrm { ft }$
B) $39 \mathrm { ft }$
C) $120 \mathrm { ft }$
D) $140 \mathrm { ft }$