Question

A hemispherical bowl is made of steel 0.25cm thick. If the inner radius of the bowl is 3.25cm then find the outer curved surface area of the bowl

Answer 1

$\large\underline{ \underline{ \sf \: Solution : \: \: \: }}$

Given ,

$\star$Inner radius (r) = 3.25

$\star$So , outer radius (R) = r + 3.25 i.e 5.25 cm

We know that ,

$\large\fbox{ \fbox{ \sf \: CSA \: of \: hemisphere = \: 2\pi {(R)}^{2} }}$

$\sf \implies CSA = 2 \times \frac{22}{7} \times {(5.25)}^{2} \\ \\\sf \implies CSA = \frac{44 \times 27.5625}{7} \\ \\\sf \implies CSA = \frac{1212.75}{7} \\ \\\sf \implies CSA = 173.25 \: \: {cm}^{2}$

Hence , the required value is 173.25 cm²

Answer 2

${\huge{\green{\underline{\underline{\pink{Aηѕωєя \: :}}}}}}$

$\small\bold{Inner \: radius \: of \: the \: bowl \: = }$ 5cm

$\small\bold{Thickness \: of \: the \: steel \: =}$ 0.25cm

$\small\bold{Outer \: radius \: of \: the \: bowl \: =}$ 5+0.25=5.25cm

$\small\bold{Outer \: Curved \: surface \: of \: the \: hemispherical \: bowl \: =}$ 2πr²

= 2× $\large\dfrac{22}{7}$ × (5.25)² = 172.25 cm²

${\huge{\red{\underline{\overline{\mathscr{\red{Hope \: This \: Helps \: You}}}}}}}$