Question

A road roller is cylindrical in shape. It's circular end has a diameter 0.7 m and its width is 2 m. Find the least number of complete revolutions that the roller must make in order to level a playground measuring 80 m by 44m?​

Answer 1

800 is the least number of complete revolutions that the roller must make in order to level a playground measuring 80 m by 44m.

Step-by-step explanation:

Given:

Here, diameter =0.7 m

$radius =\frac{diameter}{2}$

$radius =\frac{0.7}{2}$

radius = 0.35 m

height = 2 m

Total area = $80\times 44$

                  = $3520 m^2$

Curved surface area = 2πrh

                                    = $2\times \frac{22}{7} \times 0.35 \times 2$

                                    = $\frac{30.8}{7}$

                                    = $4.4 m^2$

Now, no. of revolutions = $\frac{Total area }{Curved surface area}$

                                         = $\frac{3520}{4.4}$

                                         = 800

Therefore, 800 is the least number of complete revolutions that the roller must make in order to level a playground measuring 80 m by 44m.

                                       

Answer 2

The least number of complete revolutions that the roller must make in order to level a playground is $800$

Step-by-step explanation:

Give,

Diameter of the roller cylindrical shape$=0.7\ m$

                                                  ∴Radius$=\frac{0.7}{2}=0.35\ m$

                                        And Width$(h)=2\ m$

Length and width of the playground is $80\ m\ and\ 44\ m$

Area of the Playground$=80\times 44$

                                      $=3520\ m^{2}$

Area of the roller cylindrical shape$=2\pi rh$

                                                         $=2\times \frac{22}{7}\times 0.35\times 2$

                                                         $=4.4\ m^{2}$  

∴ The least number of complete revolutions that the roller must make in order to level a playground is $=\frac{3520}{4.4}$

                                       $=800$

So, The least number of complete revolutions that the roller must make in order to level a playground is $800$