Question

If diameter of a road roller is 0.9 m and its length is 1.4 m, how much area of a field will be pressed in its 500 rotations? `(π = 22/7)`

Answer 1

Length of the road roller, h = 1.4 m

Radius of the road roller, r = `0.9/2` = 0.45 m

Now, 

Area of the field pressed in one rotation = Curved surface area of the road roller

= 2πrh

= `2 xx 22/7 xx 0.45 xx 1.4` 

= 3.96 m²

∴ Area of the field pressed in 500 rotations = 500 × Area of the field pressed in one rotation

= 500 × 3.96

= 1980 m²

Thus, the area of the field pressed in 500 rotations is 1980 m².