\

Diameter of the water tank is $\"\"$ .

\

Radius is $\"\"$ .

\

Find the total capacity of the water tank.

\

$\"\"$

\

The depth of the water is $\"\"$ .

\

$\"\"$

\

$\"\"$

\

The area of the cross section is $\"\"$ .

\

$\"\"$ .

\

\

Evaluate the integral $\"\"$ by using trigonometric substitution method:

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

The total volume of water tank is thus about $\"\"$

\

The percentage of the total capacity is,

\

$\"\"$

\

The tank is filled about $\"\"$ .

\

\

$\"\"$ .