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 91cm and
length is 1.2m.

Answer 1

Answer:

683,400 is the best option for this question

Answer 2

Given:

✰ A road roller takes 750 complete revolutions to move once over to level a road.

✰ Diameter of a road roller = 91 cm

✰ Length of road roller, i.e, height ( h ) = 1.2 m

To find:

✠ The area of the road.

Solution:

Here, in this question the area covered by the road roller in one revolution will equal to it's lateral surface area. Thus, by using formula to calculate lateral surface area, we will find area covered by road ruler in one revolution. As a road roller takes 750 complete revolutions to move once over to level a road, so we will calculate the area in 750 revolutions to find the area of the road.

➛ Diameter of a road roller = 91 cm

➛ Radius of a road roller = Diameter/2

➛ Radius of a road roller = 91/2

➛ Radius of a road roller = 45.5 cm

➛ Radius of a road roller = 44.5/100 m

[ 1 cm = 1/100 m ]

➛ Radius of a road roller = 0.455 m

Area covered by the road roller in one revolution will equal to the lateral surface area.

✭ Lateral surface area = 2πrh ✭

⟹ Lateral surface area = 2 × 22/7 × 0.455 × 1.2

⟹ Lateral surface area = 44/7 × 0.455 × 1.2

⟹ Lateral surface area = 44/7 × 0.546

⟹ Lateral surface area = 3.432 m²

Now,

➤ Area covered in one revolution = 3.432

➤ Area covered in 750 revolution = 3.432 × 750

➤ Area covered in 750 revolution = 2574 m²

∴ The area of the road = 2574 m²