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 "pi=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

`=(2xx22/7xx42xx120)cm^2`

= 31680 cm²

Area of field = 500 × CSA of roller

  = (500 × 31680) cm²

  = 15840000 cm²

`=15840000/(100xx100) m^2`

  = 1584 m²