मराठी
महाराष्ट्र राज्य शिक्षण मंडळएस.एस.सी (इंग्रजी माध्यम) इयत्ता ९ वी

If the radius of a solid hemisphere is 5 cm, then find its curved surface area and total surface area. ( π = 3.14 ) - Geometry

Advertisements
Advertisements

प्रश्न

If the radius of a solid hemisphere is 5 cm, then find its curved surface area and total surface area. ( π = 3.14 )

बेरीज
Advertisements

उत्तर

Radius of the hemisphere, r = 5 cm

∴ Curved surface area of the hemisphere = 2πr

= 2 × 3.14 × (5)2 

= 157 cm2

Total surface area of the hemisphere = 3πr

= 3 × 3.14 × (5)2 

= 235.5 cm2

Thus, the curved surface area and total surface area of the solid hemisphere is 157 cm2 and 235.5 cm2, respectively.

shaalaa.com
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 9: Surface Area and Volume - Practice Set 9.3 [पृष्ठ १२३]

APPEARS IN

बालभारती Mathematics 2 [English] Standard 9 Maharashtra State Board
पाठ 9 Surface Area and Volume
Practice Set 9.3 | Q 2. | पृष्ठ १२३

संबंधित प्रश्‍न

The radius of a spherical balloon increases from 7 cm to 14 cm as air is being pumped into it. Find the ratio of surface areas of the balloon in the two cases.


Find the radius of a sphere whose surface area is 154 cm2.

`["Assume "pi=22/7]`

 


The diameter of the moon is approximately one-fourth of the diameter of the earth. Find the ratio of their surface area.


A certain number of metallic cones, each of radius 2 cm and height 3 cm are melted and recast into a solid sphere of radius 6 cm. Find the number of cones.


On a map drawn to a scale of 1: 50,000, a rectangular plot of land ABCD has the following dimensions. AB = 6 cm; BC = 8 cm and all angles are right angles. Find:

1) the actual length of the diagonal distance AC of the plot in km.

2) the actual area of the plot in sq. km.


Two solid spheres of radii 2 cm and 4 cm are melted and recast into a cone of height 8 cm. Find the radius of the cone so formed.


The surface area of a solid metallic sphere is 2464 cm2. It is melted and recast into solid right circular cones of radius 3.5 cm and height 7 cm. Calculate:

  1. the radius of the sphere.
  2. the number of cones recast. (Take π = `22/7`)

Find the surface area of a sphere of diameter 14 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`.


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?


A hollow sphere of internal and external diameter 4 cm and 8 cm respectively is melted into a cone of base diameter 8 cm. Find the height of the cone. 


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?


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. 


The hollow sphere, in which the circus motor cyclist performs his stunts, has a diameter of 7 m. Find the area available to the motorcyclist for riding.


If a sphere of radius 2r has the same volume as that of a cone with circular base of radius r, then find the height of the cone.


The surface area of a sphere of radius 5 cm is five times the area of the curved surface of a cone of radius 4 cm. Find the height of the cone.

 

The total surface area of a hemisphere of radius r is


If the ratio of volumes of two spheres is 1 : 8, then the ratio of their surface areas is 


If a solid sphere of radius r is melted and cast into the shape of a solid cone of height r, then the radius of the base of the cone is


A cone, a hemisphere and a cylinder stand on equal bases and have the same height. The ratio of their volumes is


Find the surface area and volume of sphere of the following radius.  (π = 3.14)

4 cm


Find the surface area and volume of sphere of the following radius.  (π = 3.14 )

 9 cm


If the surface area of a sphere is 2826 cmthen find its volume. ( π= 3.14)


Find the surface area of a sphere, if its volume is 38808 cubic cm. `(π = 22/7)`


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 length of the wire of diameter 4 m that can be drawn from a solid sphere of radius 9 m. 


How many lead balls of radii 1 cm each can be made from a sphere of 8 cm radius?


Find the volume of the hollow sphere whose inner diameter is 8 cm and the thickness of the material of which it is made is 1 cm . 


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]


There is surface area and volume of a sphere equal, find the radius of sphere.


A spherical cannon ball, 28 cm in diameter is melted and recast into a right circular conical mould, the base of which is 35 cm in diameter. Find the height of the cone, correct to one place of decimal.


A sphere cut out from a side of 7 cm cubes. Find the volume of this sphere?


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 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


A solid sphere is cut into two identical hemispheres.

Statement 1: The total volume of two hemispheres is equal to the volume of the original sphere.

Statement 2: The total surface area of two hemispheres together is equal to the surface area of the original sphere.

Which of the following is valid?


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×