Advertisements
Advertisements
Question
Assuming the earth to be a sphere of radius 6370 km, how many square kilo metres is area
of the land, if three-fourth of the earth’s surface is covered by water?
Advertisements
Solution
`3^(th) /4`of earth surface is covered by water
∴ `1^(th)/4` earth surface is covered by land
∴ Surface area covered by land `- 1/4 × 4πr^2`
`- 1/4 × 4 × 22/7× 6370^2`
- `127527.4km^2`
APPEARS IN
RELATED QUESTIONS
Find the surface area of a sphere of radius 5.6 cm.
`["Assume "pi=22/7]`
Find the surface area of a sphere of diameter 3.5 m.
`["Assume "pi=22/7]`
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]`
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.
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 surface area of a sphere of diameter 21 cm.
The surface area of a sphere is 5544 `cm^2`, find its diameter.
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 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]
Find the maximum volume of a cone that can be carved out of a solid hemisphere of radius r cm.
Find the total surface area of a hemisphere of radius 10 cm.
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.
A sphere and a cube are of the same height. The ratio of their volumes is
If the surface area of a sphere is 144π m2, then its volume (in m3) is
Find the surface area and volume of sphere of the following radius. (π = 3.14)
4 cm
If the radius of a solid hemisphere is 5 cm, then find its curved surface area and total surface area. ( π = 3.14 )
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?
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?
