Question

The radius of a garden roller is 1.4 m and it is 2m long. How much area will it cover in 4 revolutions? ​

Answer 1

Step-by-step explanation:

Area covered = Curved surface × Number of revolutions

r=

2

1.4

=0.7 m

h=2 m

Curved surface = 2πrh=2×

7

22

×0.7×2=8.8 m

2

Hence,

Area covered = 8.8×5=44 m

2

Answer 2

Answer :

›»› The area levelled of a garden in 4 revolution is 70.4 m².

Step-by-step explanation :

Given :

• Radius of a garden roller = 1.4 m.
• Long or height of a garden roller = 2 m.

To Find :

• How much area will it cover in 4 revolutions?

Formula required :

Formula to calculate the curved surface area of garden roller is given by,

→ CSA = 2πrh.

Here,

• CSA is the Curved surface area of garden roller.
• The value of π is 22/7.
• r is the Radius of garden roller.
• h is the Height of garden roller.

Units,

• The unit of Curved surface area is m².
• The unit of radius is m.
• The unit of Height is m.

Formula to calculate the area levelled of a garden in 4 revolution is given by,

→ CSA * 4 revolution.

Solution :

First we will find the curved surface of garden roller.

We know that, if we are given with the radius of garden roller and height of roller garden then we have the required formula, that is,

→ CSA = 2πrh.

By using the formula to calculate the the curved surface area of garden roller and substituting all the given values in the formula, we get :

→ CSA = 2 * 22/7 * 1.4 * 2

→ CSA = 2 * 22/7 * 14/10 * 2

→ CSA = 2 * 22 * 2/10 * 2

→ CSA = 2 * 22 * 2/5

→ CSA = 44 * 2/5

→ CSA = 8.8 * 2

→ CSA = 17.6.

∴ The curved surface of garden roller is 17.6 m².

Now,

Area levelled of a garden in 4 revolution = Curved surface area of garden roller * 4 revolution.

→ Area covered = 17.6 * 4

→ Area covered = 70.4.

Hence, the area levelled of a garden in 4 revolution is 70.4 m².