Question

Hii friends

The length of a roller is 91 cm and its radius is 30 cm. If it rotates 100 times, how many m sq. of land will be levelled???

Answer 1

As roller is a cylinder
h=91cm
r=30cm

Its curved surface area = 2πrh
= 2 × 3.14 × 30 × 91
= 17144.4 cm²

In one round it levells 17144.4cm²
In 100 rounds it will levell 17144.4×100 cm²
= 1714440 cm²

Answer 2

Given length of a roller h = 91 cm.

Given radius r = 30 cm.

We know that curved surface area of the roller = 2πrh

= > 2 * (22/7) * (30) * (91)

= > 2 * 22 * 30 * 13

= > 17160 cm^2.

So, the area leveled in one rotation = 17160 cm^2.

Given that it rotates 100 times.

Then, Area levelled in 100 times = 100 * 17160 cm^2

= > 1716000 cm^2

= > 171.6 m^2.

Therefore, the area of the land leveled = 171.6m^2.

Hope this helps!