Question

A cylindrical tank $7$ m in diameter, contains water to a depth of $4$ m. What is the total area of wetted surface?

• A. $110$ sq. m
• B. $126.5$ sq.
• C. $131.5$ sq. m
• D. $136.5$ sq. m

Answer 1

Answer: (B)

$126.5$ sq.

Given, $2r=7$
$\Rightarrow r=7/2;h=4$
Area of wetted surface $=$ CSA of cylinder $ABCD$ $+$ Area of base (Circle)
$=2\pi rh=\pi r^2$
$=\pi r(2h+r)$
$=\frac{22}{7}\times \frac{7}{2}(8+3.5)$
$=11\times 11.5=126.5$ sq. m