Question

The diameter of a roller is 84 cm and its length is 120 cm . It takes 500 complete revolutions to move once over to level a playgroup. Find the area of the playground in m².

Answer 1

$\huge{\underline{\underline{\sf{\blue{SOLUTION:-}}}}}$

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$\sf{\underline{\pink{Answer-}}}$

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• Area of the playground is 1584m².

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$\sf{\underline{\pink{Given-}}}$

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• The diameter of a roller is 84 cm and its length is 120 cm . It takes 500 complete revolutions to move once over to level a playgroup.

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$\sf{\underline{\pink{We\:Have\:To\:Find-}}}$

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• Area of the playground in m².

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$\sf{\underline{\pink{Explanation-}}}$

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➨⠀$\sf \: Diameter \: = \: 84cm$

➨⠀$\sf \: As \: we \: know \: Radius =\frac{Diameter}{2}$

➨⠀$\sf \: Radius = \frac{84}{2} = 42 {cm}^{2}$

➨⠀$\sf \: H= 120cm$

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$\sf\underline{\blue{Formula\:used\: here-}}$

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$\bigstar \: \boxed{ \sf \: Total \: surface \:area \:of\: cylinder = 2\pi r(h+r) }$

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$\sf\underline{\blue{Now\: putting\: the \: value-}}$

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➨⠀$\sf \: 2 \times \frac{22}{7} \times 42(120 + 42)$

➨⠀$\sf \: 44 \times 6 \: + 162$

➨⠀$\sf \: 264 + 162$

➨⠀$\sf \: 426 \times 500$

➨⠀$\sf \: 31680 {cm}^{2}$

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$\sf{\blue{Area \: levelled \: =Area \: of \: Playground}}$

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➨⠀$\sf \: 500 \times 31680 {cm}^{2}$

➨⠀$\sf \: 15840000 {cm}^{2}$

➨ $\sf \: \frac{1584000}{1000}$

➨⠀${\sf 1584 {m}^{2}}$

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$\boxed{\sf \: Hence \: the \: area \: of \: playground \: is \: 1584 {m}^{2}}$

Answer 2

Answer:

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