Question

The diameter of a garden roller is 1.4m and it is 4m long. How much area will it cover in 5

revolutions? ​

Answer 1

Given:-

• Diameter of Garden roller is 1.4 m.

• Height of Roller is 4 m.

• Roller cover 5 revolution around the garden.

To Find:-

• Area covered by Roller in 5 revolutions.

Solution:-

Here, Curved Surface Area of Roller ( Cylinder ) is 2πrh.

So, Radius of Roller ⇒ $\dfrac{Diameter}{2}$           ⇔ $\dfrac{1.4}{2}$ m

                                 ⇒ 0.7 m

Height of roller ⇒ 4 m

Now, Curved Surface Area of Roller ⇒ 2πrh

                                                            ⇒ 2 × $\dfrac{22}{7}$ × 0.7 × 4 m²

                                                            ⇒ 17.6 m²

∵ Curved Surface Area of Roller is 17.6 m².

So, Area covered by roller in 5 revolutions ⇒ 5 × Curved Surface Area of Roller

                                                                       ⇒ 5 × 17.6 m²

                                                                       ⇒ 88 m²

Hence, Area covered by roller in 5 revolutions is 88 m².

Some Important Terms:-

• Total Surface Area of Cylinder = 2πr ( r + h )

• Volume of Cylinder = πr²h

• Volume of cone = $\dfrac{1}{3}$ πr²h

• Total Surface Area of Cone = πr ( l + r )

Answer 2

$\red{\textbf{Answer :-}}$$88 {m}^{2}$

$\LARGE\textsf{Given :-}$

$\textsf{diameter of a garden roller is 1.4 m}$

$r = \LARGE \frac{1.4}{2}$

$= 0.7m$

$\textsf{h= 4 m}$

$\textsf{now,}$

$\textsf{Curved surface = 2πrh}$

$2 \times \LARGE \frac{22}{7} \small \times 0.7 \times 4$

$= 17.6 {m}^{2}$

$\textsf{Area covered = Curved surface × Number of revolutions</p><p>}$

$= 17.6 \times 5 = 88$

$\red{\textbf{so , Area =}}$$88 {m}^{2}$

$\red{\textbf{More information :-}}$

• Calculating a square area is as easy as multiplying the length by the width.

• Calculating a square area is as easy as multiplying the length by the width.

• surface area of a cylinder can be calculated with the height and radius using the formula 2 pi r^2 + 2 pi r h.