Question

Hey plz anyone help me in my question:-

Ques:- Diameter and length of roller are 84cm and 120cm respectively. In how many revolution, can the roller level the playground of area 1584m^2

Please tell it fast.

Answer 1

In one rotation, roller covers an area of 2*pi*84*120

So, total number of revolutions = 1584*100*2*100/(2*22/7*84*120)

                                                     = 500

Answer 2

Find the radius:

Radius = Diameter ÷ 2

Radius = 84 ÷ 2 = 42 cm

Convert all units to m:

Radius = 42 cm = 0.42m

Length = 120 cm = 1.2m

Find the lateral surface area:

Lateral Surface Area = 2πrh

Lateral Surface Area = 2π(0.42)(1.2) = 3.168 m²

Find the number of revolutions:

3.168 m² = 1 revolution

1584 m² = 1584 ÷ 3.168 = 500

Answer: The roller needs to roll 500 revolution to cover an area of 1584 m²