Question

The diameter of a roller is 84 cm and it's length is 120 cm it's takes500 complete revolutions to move once over to level a playground find the area of the playground in meter square

Answer 1

Answer:

hop you understand the above problem

Answer 2

15840 $cm^2$

Step-by-step explanation:

Given d =   84cm

          r = $\frac{d}{2}=\frac{84}{2}=42cm$

Length of roller is 120cm

Number of complete revolutions=500

In one revolution the roller will cover an area equal to its lateral surface.

$\therefore$ 1 revolution area of the road = $2\pi rh$

$2\times\frac{22}{7}\times 42\times120\\\Rightarrow31680cm^2$

In 500 revolution area of road cover

$(500\times31680)\\\Rightarrow15840000m^2\\\Rightarrow15840cm^2$