Question

A road roller takes 750 complete revolutions to move once over to level a road. Find the area of the road if the diameter of a road roller is 84 cm and length is 1 m.

Answer 1

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

Thus, in 1 revolution, area of the road covered = 2πrh

= `2 xx 22/7` × 42 cm × 1m

= `2 xx 22/7 xx 42/100` m × 1 m

= 2.64 m²

In 750 revolutions, area of the road covered

= 2.64 × 750 m²

= 1980 m²

Therefore, total area of this road = 1980m²