Advertisements
Advertisements
प्रश्न
A sphere has the same curved surface area as the curved surface area of a cone of height 36 cm and base radius 15 cm . Find the radius of the sphere .
Advertisements
उत्तर
Radius of cone = 15 cm
Height of cone = 36 cm
Curved surface of the cone = `pirl`
`l = sqrt(r^2 + h^2) = sqrt(15^2 + 36^2) = sqrt(1521) = 36`
Curved surface of cone = `22/7 xx 15 xx 39 = 1838.571` cm2
Curved surface of cone = Curved surface of sphere
⇒ `4pir^2 = 1838.571`
⇒ `4 xx 22/7 xx r^2 = 1838.571`
⇒ `r^2 = (1838.571 xx 7)/(4 xx 22)`
⇒ `r^2 = 146.25`
⇒ r = 12.09 cm
The radius of the sphere = 12.09 cm
APPEARS IN
संबंधित प्रश्न
Find the surface area of a sphere of diameter 3.5 cm.
A hollow sphere of internal and external radii 6 cm and 8 cm respectively is melted and recast into small cones of base radius 2 cm and height 8 cm. Find the number of cones.
A largest sphere is to be carved out of a right circular cylinder of radius 7 cm and height 14 cm. Find the volume of the sphere.
A solid is in the form of a cone standing on a hemi-sphere with both their radii being equal to 8 cm and the height of cone is equal to its radius. Find, in terms of π, the volume of the solid.
If the radius of a solid hemisphere is 5 cm, then find its curved surface area and total surface area. ( π = 3.14 )
The radius of a sphere is 9 cm. It is melted and drawn into a wire of diameter 2 mm. Find the length of the wire in metre.
Find the radius of the sphere whose surface area is equal to its volume .
How many lead balls of radii 1 cm each can be made from a sphere of 8 cm radius?
From a rectangular solid of metal 42 cm by 30 cm by 20 cm, a conical cavity of diameter 14 cm and depth 24 cm is drilled out. Find: the volume of remaining solid
Find the volume and surface area of a sphere of diameter 21 cm.
