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 playground. Find the area of the playground in m2

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Answer 1

Given :

• Diameter of Roller is 84 cm.
• Length /Height of Roller is 120 cm.

To Find :

• Area of Playground in m².

Solution :

$\longmapsto\tt{Radius=\dfrac{84}{2}=42\:cm}$

$\longmapsto\tt{Height=120\:cm}$

Using Formula :

$\longmapsto\tt\boxed{C.S.A\:of\:Cylinder=2\pi{rh}}$

Putting Values :

$\longmapsto\tt{2\times\dfrac{22}{{\cancel{7}}}\times{{\cancel{42}}}\times{120}}$

$\longmapsto\tt{44\times{6}\times{120}}$

$\longmapsto\tt\bf{31680\:{cm}^{2}}$

So , Area of 1 revolution is 31680 cm² ....

Now ,

Area of 500 revolutions :

$\longmapsto\tt{31680\times{500}}$

$\longmapsto\tt\bf{15840000\:{cm}^{2}}$

In m² :

$\longmapsto\tt{\dfrac{1584{\cancel{0000}}}{1{\cancel{0000}}}}$

$\longmapsto\tt\bf{1584\:{m}^{2}}$

Answer 2

here is ur answer.........