Question

The capacity of a closed cylindrical vessel of height 1 m is 15.4 l. How many square metres of the metal sheet would be needed to make it? [3 MARKS]

Answer 1

Formula: 1 Mark
Application: 1 Mark
Solution: 1 Mark

Capacity of cylindrical vessel $=\pi r^{2}h=15.4l,whereh=1m=100cm$
$\Rightarrow \frac{22}{7}\times r^2\times 100=\frac{154}{10}\times 1000c{m}^3$
$\Rightarrow r^2=49\Rightarrow r=7cm$
$\therefore$ Area of metal sheet required $=2\pi r(r+h)=2\times \frac{22}{7}\times \frac{3}{4}\times 7(7+100)=44\times 107=4708c{m}^2=\frac{4708}{100\times 100}{m}^2=0.4708m^2$