The College of Engineering has an emergency water tank that is cylindrical and $4$ feet high. The tank is initially filled with water at $60F$ and has a $3-$foot diameter opening to the atmosphere at the top. The outlet at the bottom of the tank with a diameter of $0\mathrm{.}5$ inches is opened and water begins to empty out of the tank. The average velocity of the water exiting the tank is given by Torricelli's law as $v=(2gh{)}^{\frac{1}{2}},$ where $h$ is the height of the water above the center of the outlet port and $g$ is the acceleration due to gravity. Ignoring any water loss through the top opening, determine a$)$ how long it will take the water level to drop to $1ft$ from the bottom; and b$)$ how long it will take to drain the entire tank.