a road roller takes 800 complete revolutions to move once over to level a road. find the area of the road if the diameter of the road roller is 91 cm and length is 1 m. also find the cost of levelling if it cost rs 150 per m²
please answer its very urgent
Answers
ATQ, a road roller takes 800 complete revolutions to move once over to level a road.
given :-
diameter = 98cm
therefore radius = 98/2 = 49cm
length (height) = 1m = 100cm
we know that a road roller is basically cylindrical. so we can use the formula of CSA of cylinder.
CSA of the road roller = 2πrh
= 2 × 22/7 × 49 × 100
= 44 × 7 × 100
= 30800cm²
now we have to find the area of the road if it takes 800 complete revolution to level the road.
simply multiply the CSA with 800 and u will get ur answer.
= 800 × 30800
= 24640000cm²
hence, the area of the road is 24640000cm².
solving for the question which u posted in comment section...
the walls and the ceiling of a hall 20m × 16m × 10m are to be painted from each can of paint 130m² of area is painted. how many cans are required to paint the room?
ans :-
dimensions of hall is given = 20m × 16m × 10m
length = 20m, breadth = 16m and height = 10m
first we have to find the area of four walls and the ceiling.
so we will use the formula CSA + 1 base
CSA + 1 base of the hall = 2h(l + b) + lb
= 2 × 10(20 + 16) + (20 × 16)
= 20(36) + 320
= 720 + 320
= 1040m²
ATQ, one can of paint can paint 130m²
therefore no. of cans required = 1040/130
= 8
hence, 8 cans of paint are required.
solving for next question u posted in comment section..
• if the volume of a cylinder is 3080cm³ and the base radius is 7cm. find the height of the cylinder also find a) curved surface area b) total surface area.
given volume of the cylinder = 3080cm³
radius = 7cm
we know the formula for the volume of a cylinder. that is πr²h
therefore πr²h = 3080cm³
=> 22/7 × 7 × 7 × h = 3080cm³
=> 22 × 7 × h = 3080cm³
=> 154 × h = 3080cm³
=> h = 3080/154
=> h = 20cm
the height of the cylinder is 20cm.
a) curved surface area of the cylinder = 2πrh
= 2 × 22/7 × 7 × 20
= 44 × 20
= 880cm²
b) TSA of the cylinder = 2πr(h + r)
= 2 × 22/7 × 7(20 + 7)
= 44 × 27
= 1188cm²