Advertisements
Advertisements
प्रश्न
Find the surface area of a sphere, if its volume is 38808 cubic cm. `(π = 22/7)`
Advertisements
उत्तर
Let the radius of the sphere be r cm.
Volume of the sphere (V) = 38808 cm3
Volume of the sphere (V) = `4/3πr^3`
⇒ 38808 = `4/3 xx 22/7 xx r^3`
⇒ r3 = `[38808 xx21]/88` = 9261
⇒ r3 = 9261
⇒ r3 = `root3(9261)`
⇒ r = 21 cm
∴ Surface area of the sphere = 4πr2
= `4 xx 22/7 xx (21)^2`
= 5544 cm2
Thus, the surface area of the sphere is 5544 cm2.
APPEARS IN
संबंधित प्रश्न
Find the total surface area of a hemisphere of radius 10 cm. [Use π = 3.14]
Find the radius of a sphere whose surface area is 154 cm2.
`["Assume "pi=22/7]`
A hemispherical bowl is made of steel, 0.25 cm thick. The inner radius of the bowl is 5 cm. Find the outer curved surface area of the bowl.
`["Assume "pi = 22/7]`
A right circular cylinder just encloses a sphere of radius r (see figure). Find
- surface area of the sphere,
- curved surface area of the cylinder,
- ratio of the areas obtained in (i) and (ii).
A solid sphere of radius 15 cm is melted and recast into solid right circular cones of radius 2.5 cm and height 8 cm. Calculate the number of cones recast.
A solid cone of radius 5 cm and height 8 cm is melted and made into small spheres of radius 0.5 cm. Find the number of spheres formed.
Find the surface area of a sphere of diameter 21 cm.
A wooden toy is in the form of a cone surmounted on a hemisphere. The diameter of the base
of the cone is 16 cm and its height is 15 cm. Find the cost of painting the toy at Rs. 7 per 100
`cm^2`.
The diameter of the moon is approximately one fourth of the diameter of the earth. Find the
ratio of their surface areas.
The surface area of a sphere is 2464 cm2, find its volume.
A spherical ball of lead has been melted and made into identical smaller balls with radius equal to half the radius of the original one. How many such balls can be made?
How many balls each of radius 1 cm can be made by melting a bigger ball whose diameter is 8 cm?
The surface area of a solid sphere is increased by 12% without changing its shape. Find the percentage increase in its:
- radius
- volume
A solid sphere of radius 15 cm is melted and recast into solid right circular cones of radius 2.5 cm and height 8 cm. Calculate the number of cones recast.
The total area of a solid metallic sphere is 1256 cm2. It is melted and recast into solid right circular cones of radius 2.5 cm and height 8 cm. Calculate :
- the radius of the solid sphere.
- the number of cones recast. [Take π = 3.14]
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.
Find the maximum volume of a cone that can be carved out of a solid hemisphere of radius r cm.
What is the least number of solid metallic spheres, each of 6 cm diameter, that should be melted and recast to form a solid metal cone whose height is 45 cm and diameter 12 cm?
The cross-section of a tunnel is a square of side 7 m surmounted by a semi-circle as shown in the adjoining figure. The tunnel is 80 m long.
Calculate:
- its volume,
- the surface area of the tunnel (excluding the floor) and
- its floor area.
Find the volume of a sphere whose surface area is 154 cm2.
How many spherical bullets can be made out of a solid cube of lead whose edge measures 44 cm, each bullet being 4 cm in diameter?
The largest sphere is cut off from a cube of side 6 cm. The volume of the sphere will be
If the ratio of volumes of two spheres is 1 : 8, then the ratio of their surface areas is
A cone, a hemisphere and a cylinder stand on equal bases and have the same height. The ratio of their volumes is
If the radius of a solid hemisphere is 5 cm, then find its curved surface area and total surface area. ( π = 3.14 )
Find the radius of the sphere whose surface area is equal to its volume .
A hemispherical bowl of internal radius 9 cm is full of liquid. This liquid is to be filled into conical shaped small containers each of diameter 3 cm and height 4 cm. How many containers are necessary to empty the bowl?
The total area of a solid metallic sphere is 1256 cm2. It is melted and recast into solid right circular cones of radius 2.5 cm and height 8 cm. Calculate: the number of cones recasted [π = 3.14]
Find the volume and surface area of a sphere of diameter 21 cm.
The volume of a sphere is 905 1/7 cm3, find its diameter.
A sphere cut out from a side of 7 cm cubes. Find the volume of this sphere?
The radius of a sphere is 10 cm. If we increase the radius 5% then how many % will increase in volume?
The surface area of a solid metallic sphere is 616 cm2. It is melted and recast into smaller spheres of diameter 3.5 cm. How many such spheres can be obtained?
A spherical ball of radius 3 cm is melted and recast into three spherical balls. The radii of two of the balls are 1.5 cm and 2 cm. Find the diameter of the third ball.
The radius of a sphere increases by 25%. Find the percentage increase in its surface area
The total surface area of a hemisphere is how many times the square of its radius
