Question

the radius of a roller is0.7m and 2m long. then the area covered by it in 10 revolutions is

Answer 1

Heya !!!

This is your answer...
Given ....
Radius = 0.7 m = 7/10 m.
Length = 2 m.

No. of revolutions = 10.

We know that the area covered in one revolution will be equal to CSA of roller.

CSA = 2× pi ×rh
= 2 × 22/7 × 7/10 × 2.
= 4 × 22 × 1/10
= 88/10 = 8.8 m^2.

In 10 revolutions...
8.8 × 10 = 88 m^2.

Hence the area covered in 10 revolutions is 88 m^2.

Hope it helps....

Answer 2

Heya,

It is given that,

Radius = 0.7m
Length = 2m
Revolution = 10

To find the area,

CSA = 2πrh
CSA = 2 × 22/7 × 0.7 × 2
CSA = 2 × 22 × 0.1 × 2
CSA = 44 × 0.2
CSA = 8.8m^2

Area covered in 10 revolution = 8.8 × 10 = 88m^2

This can be done in another method.

Circumference = 2πr
Circumference = 2 × 22/7 × 0.7
Circumference = 2 × 22 × 0.1
Circumference = 44 × 0.1
Circumference = 4.4m

Length = 2 = 2 × 4.4 = 8.8

Area = 8.8 × 10 = 88m^2

Hope my answer helps you :)

Regards,
Shobana