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?    [ Assume π = 22/7 ]

Answer 1

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 = (84/2)cm = 42cm

CSA of roller = 2πrh

= (2 x 22/7 x 42 x 120)cm²

= 31680cm²

Area of field = 500 × CSA of roller

= (500 × 31680) cm²

= 15840000 cm²

= 1584 m²