Question

find the volume and the total surface area of a hemisphere of radius 3.5 CM​

Answer 1

Answer:

use the formula 2/3πr^3

Answer 2

GivEn:

• Radius of hemisphere, r = 3.5 cm

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Need to find:

• Volume and TSA of hemisphere

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$\setlength{\unitlength}{1cm}\begin{picture}(6, 4)\linethickness{0.26mm}\qbezier(5.8,2.0)(5.8,2.3728)(4.9799,2.6364)\qbezier(4.9799,2.6364)(4.1598,2.9)(3.0,2.9)\qbezier(3.0,2.9)(1.8402,2.9)(1.0201,2.6364)\qbezier(1.0201,2.6364)(0.2,2.3728)(0.2,2.0)\qbezier(0.2,2.0)(0.2,1.6272)(1.0201,1.3636)\qbezier(1.0201,1.3636)(1.8402,1.1)(3.0,1.1)\qbezier(3.0,1.1)(4.1598,1.1)(4.9799,1.3636)\qbezier(4.9799,1.3636)(5.8,1.6272)(5.8,2.0)\put(3,2){\line(1,0){2.8}}\put(3.6,1.6){\sf{3.5 cm}}\put(3,2.02){\circle*{0.15}}\qbezier(0.17,2)(3,-2.9)(5.8,1.9)\end{picture}$

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We know that,

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$\star\;{\boxed{\sf{\purple{Volume_{\;(hemisphere)} = \dfrac{2}{3} \pi r^3}}}}$

$:\implies\sf \dfrac{2}{3} \times \dfrac{22}{7} \times 3.5 \times 3.5 \times 3.5$

$:\implies\sf \dfrac{2}{3} \times \dfrac{22}{7} \times \dfrac{7}{2} \times \dfrac{7}{2} \times \dfrac{7}{2}$

$:\implies\sf \dfrac{11 \times 49}{3 \times 2}$

$:\implies{\boxed{\frak{\pink{89.83\;cm^3}}}}\;\bigstar$

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☯ Now, Finding Total Surface Area of hemisphere,

$\star\;{\boxed{\sf{\purple{Volume_{\;(hemisphere)} = 3 \pi r^2}}}}$

$:\implies\sf 3 \times \dfrac{22}{7} \times 3.5 \times 3.5$

$:\implies\sf 3 \times \dfrac{22}{7} \times \dfrac{7}{2} \times \dfrac{7}{2}$

$:\implies\sf \dfrac{231}{2}$

$:\implies{\boxed{\frak{\pink{115.5\;cm^2}}}}\;\bigstar$

$\therefore\;{\underline{\sf{Hence,\; Volume\;and\;TSA\;of\; hemisphere\;is\;89.83\;cm^3\;and\;115.5\;cm^2\; respectively.}}}$