Question

the diameter of a roller is 84cm and its length is 120m l. it takes 500 complete revolutions to make once over the level of the playground. find the area of playground?

Answer 1

Radius of roller = 42 cm = 0.42 m
Length of roller = 120m
Curved surface area of roller = 2×pi×R×l
= 2 × 3.14 × 0.42 × 120
= 6.28 × 50.4 m sq.
Area of playground = 500 × 6.28 × 50.4
= 158256 m sq.