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 m^2.

Answer 1

Answer:

Radius of the roller ( r ) = 84/2 cm = 42 cm

Length of the roller ( h ) = 120 cm

Area of the playground levelled in taking 1 complete revolution 2πrh

⇏2 × 22/7 × 42 × 120 = 31680 cm²

Area of the playground

⇏31680 × 500 = 15840000 cm²

( 15840000/100 × 100 ) m² = 1584 m²

Hope it Helps uh....

Answer 2

Radius = 84/2 = 42 cm

Area of roller = Curved surface area

                      = $2\pi rh$

                      = 2*22/7*42*120 cm^2

                      = 31680 cm^2

Area of one revolution = area of roller = 31680 cm^2

Area of 500 revolution = 500*31680 cm^2

                                      = 15840000 cm^2

1584*1/100*1/00 = 1584 m^2