On an expressway, the recommended safe distance between cars in feet is given by $0.014 v ^ { 2 } + 1.05 v - 4,$ where v is the speed of the car in miles per hour. Find the safe distance when $v = 85$ miles per hour. Round your answer to the nearest tenth.
A)116.5 feet
B)186.4 feet
C)256.3 feet
D)279.6 feet
E)139.8 feet

Question

Quizplus · Accepted Answer

Plugging $v = 85$ into the formula gives the safe distance as $0.014(85)^2 + 1.05(85) - 4$, which calculates to approximately 186.4 feet.

On an Expressway, the Recommended Safe Distance Between Cars in Feet