Use a Calculator to Find the Function Value $\mathrm { R }$

Use a calculator to find the function value. Give your answer rounded to seven decimal places, if necessary.
-A formula used by an engineer to determine the safe radius of a curve, $\mathrm { R }$ , when designing a particular road is: $\mathrm { R } = \frac { \mathrm { V } ^ { 2 } } { \mathrm {~g} ( \mathrm { f } + \tan \alpha ) }$ , where $\alpha$ is the superelevation of the road and $\mathrm { V }$ is the velocity (in feet per second) for which the curve is designed. If $\alpha = 3.5 ^ { \circ } , \mathrm { f } = 0.1 , \mathrm {~g} = 30$ , and $\mathrm { R } = 1357.01 \mathrm { ft }$ , find V. Round to the nearest foot per second.

A) $V = 84 \mathrm { ft }$ per sec
B) $V = 79 \mathrm { ft }$ per sec
C) $V = 81 \mathrm { ft }$ per sec
D) $\mathrm { V } = 77 \mathrm { ft }$ per sec