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
It can be observed that a roller is cylindrical
Height (h) of cylindrical roller = Length of roller
= 120 cm
Radius (r) of the circular end of roller = 
= 42 cm
Curved Surface Area (CSA) of roller = 2πrh
= 2 * 
* 42 * 120 cm2
= 31680 cm2
Area of field = 500 × CSA of roller
= (500 × 31680) cm2
= 15840000 cm2
= 1584 m2 (∵ 1 m2 = 10000 cm2)
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