Question

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

Answer 1

HEY DEAR ... ✌️

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Here's , Your Answer :-

=) Given,
Diameter = d = 84cm

Radius (r) = d/2 = 42cm ( radius is half of diameter)

Length (l)= 120 cm

we know ,
T.S.A of cylinder = 2πrh
                           = 2 x 22/7 x 42 x 120
                           = 31680 cm^2

Area levelled by 500 revolution = Area of playground
= 500 x 31680cm^2

= 15840000 cm^2

changing m to cm .

= 1584 m^2

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HOPE , IT HELPS ... ✌️

Answer 2

Hii dear here is your answer


Radius of the roller (r) = 84/ 2 cm = 42 cm 

Length of the roller (h) = 120 cm 

Curved surface area of the roller = 2πrh 

= 2 × 22/ 7 × 42 × 120 cm2 = 44 × 720 cm2= 31680 cm2 

∴ area covered by the roller in 1 revolution = 31680 cm2 

∴ area covered by the roller in 500 revolutions = 31680 × 500 cm2 = 15840000 cm

Hence, area of the playground = 15840000/ 100× 100 m2 = 1584 m2 Ans.




Hope it's help u