Advertisements
Advertisements
प्रश्न
A cylindrical roller 2.5 m in length, 1.75 m in radius when rolled on a road was found to cover the area of 5500 m2. How many revolutions did it make?
उत्तर
Given: length of cylindrical roller, i.e., height of the cylinder, h = 2.5 m
Radius of cylindrical roller, r = 1.75 m
The cylindrical roller will roll on the road only from its curved surface.
So, curved surface area of cylindrical roller, CSA = 2πrh
⇒ CSA = 2 × `22/7` × 1.75 × 2.5 = 27.5 m2
⇒ Area of road covered in 1 revolution = 27.5 m2
And given that, total area of road covered = 5500 m2
So, number of revolutions made by road roller to cover 5500 m2 = `5500/27.5` = 200
Thus, it made 200 revolutions.
APPEARS IN
संबंधित प्रश्न
Curved surface area of a right circular cylinder is 4.4 `m^2`. If the radius of the base of the cylinder is 0.7 m, find its height.
Find the lateral curved surface area of a cylinderical petrol storage tank that is 4.2 m in diameter and 4.5 m high. How much steel was actually used, if `1/12` of steel actually used was wasted in making the closed tank?
A cylindrical vessel open at the top has diameter 20 cm and height 14 cm. Find the cost of tin-plating it on the inside at the rate of 50 paise per hundred square centimetre.
Find the volume of a cylinder whose r = 3.5 cm, h = 40 cm .
A well with 14 m diameter is dug 8 m deep. The earth taken out of it has been evenly spread all around it to a width of 21 m to form an embankment. Find the height of the embankment.
The height of a right circular cylinder is 10.5 m. Three times the sum of the areas of its two circular faces is twice the area of the curved surface. Find the volume of the cylinder.
A cylindrical container with diameter of base 56 cm contains sufficient water to submerge a rectangular solid of iron with dimensions 32 cm × 22 cm × 14 cm. Find the rise in the level of the water when the solid is completely submerged.
Find the total surface area of a closed cylindrical drum if its diameter is 50 cm and height is 45 cm. (π = 3.14)
A well with 14m diameter is dug 21m deep. The earth taken out of it has been evenly spread all around it to a width of 14m to form an embankment. Find the height of the embankment.
The radius of a solid cylinder decreases by 10% and its height increases by 20%. Find the change in percentage of its volume and curved surface area
