The formula for the minimum sag length L is Upper L equals StartFraction $2700$ Over h plus $3$ tangent alpha EndFraction

$,$ where h represents the height of the headlights above the road$$ surface, and alpha represents a small$($upward$)$ angle associated with the vertical alignment of the headlights. Calculate the minimum length L of a typical sag curve on a highway with a$40-$mile$-$per$-$hour speed limit for a car with headlights $2\mathrm{.}5$ feet above the ground and alignment set at alphaequals$1\mathrm{.}3$degrees.