Question

Please Question 9 solve

Answer 1

Diameter = 84cm. Radius = 42 cm.
Length = Height =1m=100cm.
As a roller makes one whole revolution, the area covered by it is equal to the curved surface area of roller (cylinder).
Curved surface area = 2pirh
= 2×22/7×42×100
= 26400 cm^2

Answer 2

Given Diameter of a road roller d = 84cm.

Then the radius of the road roller r = d/2

                                                         = 84/2

                                                         = 42cm.


Given the length of the road roller = 1m.

                                                          = 100cm.


Area leveled by the roller in 1 revolution = 2pirh

                                                                    = 2 * 22/7 * 42 * 100

                                                                    = 2 * 22 * 6 * 100

                                                                   = 26400cm^2.

                                                                   = 2.64m^2.



Therefore the distance covered by the road roller in 750 revolutions:

= 750 * 2.64

= 1980m^2.


Hope this helps!