Question

A road roller takes one revolution while moving down a
road. If its radius is 70 cm and width is 120 cm, find the area
covered by it in one revolution.​

Answer 1

➠Question:-

A road roller takes one revolution while moving down a road. If its radius is 70 cm and width is 120 cm, find the areacovered by it in one revolution.

➠Given:-

•Radius of the road roller(r) =70 cm

• Width of the road roller (h) =120 cm

➠To find out :-

•Area covered by it in one revolution

➠Formula used:-

C•S•A of hollow cylinder =2πrh

➠Solution:-

As road roller complete 1 revolution so it covers whole area of cylinder i.e, curved surface area of cylinder.So in order to find the required area which has to be covered by one revolution we will find CSA of the cylinder

⇒CSAᶜʸˡᶤᶰᵈᵉʳ=2πrh

⇒CSAᶜʸˡᶤᶰᵈᵉʳ=2×22/7×70×120

⇒CSAᶜʸˡᶤᶰᵈᵉʳ=440×120

⇒CSAᶜʸˡᶤᶰᵈᵉʳ=52800 cm²

Therefore ,

The required area which has to covered in one revolution by roller =52800cm²

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More to know

➠CSAᶜʸˡᶤᶰᵈᵉʳ=2πrh sq.unit

➠TSAᶜʸˡᶤᶰᵈᵉʳ=2πr(h+r) sq.unit

➠Volumeᶜʸˡᶤᶰᵈᵉʳ=πr²h sq.unit

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