Question

The diameter of a garden roller is 2.8 m and it is 1.5 m long. how much area will it coverin 100revolutions

Answer 1

Lateral surface area of a cylinder=2x pia x r x h
Radius=2.8/2=1.4
so,2x22/7x1.4x1.5
=44x0.2x1.5
=8.8x5.5
=48.4msquare
Area covered in 100 revolutions
=48.4x100=4840msquare

Answer 2

Given:

$\text{Diameter of the garden roller = 2.8 m}$

$\text{The garden roller is 1.5 m long}$

To Find:

$\text{Area covered after 100 revolutions}$

Formula:

$\text{Lateral urface area of a cylinder} = 2\pi rh$

Explanation:

$\text{The garden roller is in the shape of a cylinder. }$

$\text{The lateral surface area will come in contact with the garden on every revolution. }$

Solution:

Find the lateral surface area of the garden roller:

$\text{Lateral surface area of a cylinder} = 2\pi rh$

$\text{Lateral surface area of the roller} = 2\pi (2.8 \div 2)(1.5)$

$\text{Lateral surface area of the roller} = 4.2\pi \text{ m}^2$

Find the area covered in 100 revolutions:

$\text{1 revolution }= 4.2\pi$

$\text{100 revolutions }= 4.2\pi \times 100$

$\text{100 revolutions }= 420 \pi$

$\text{100 revolutions }= 1320 \text{ m}^2$

$\boxed{\textbf{Answer: The area is 1320 m}^2}$