Question

the diameter of a roller is 84 cm and its length is 120 cm. it takes 500 revolution moving once over to level a play ground .what is the area of the playground.

Answer 1

diameter of the roller =d=84cm
redius =r=d/2=84/2=42cm
length=h=120cm
area covers for one revolution = csa of the cylinder
=2*pi*rh
area covered to level in 500 revolutions=500*2*pi*r*h
=1000*22/7*42*120
=1000*22*6*120
=15840000 cm^3

Answer 2

given length of roller = 120cm
diameter of roller = 84 cm
Therefore,
radius = 42 cm
circumference will be = 2× 22/7 ×42
= 264 cm
Now , area of the road will be =
[(No. of revolutions)×(circumference of roller)]× (length of roller)
= 500 × 264 × 120
=15840000 cm sq
= 1584 m sq