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 `m^2`.

Explanation

Here, length `h = 84 cm`
Diameter `2r = 120 cm`
`rArr r = 60 cm`
Area of the ground covered in one rotation = curved surface area
`= 2pi rh`
`=2xx(22)/(7)xx60xx84`
`=31680 cm^(2)`
`therefore` Area of ground covered in 500 rotations `= 500xx31680 cm^(2)`
`=(500xx31680)/(100xx100)m^(2)=1584 m^(2)`
`therefore` Area of playground `= 1584 m^(2)`