Advertisements
Advertisements
प्रश्न
Find the surface area of a sphere of diameter 3.5 m.
`["Assume "pi=22/7]`
Advertisements
उत्तर
Radius (r) of sphere = `"Diameter"/2`
= `3.5/2`
= 1.75 m
Surface area of sphere = 4πr2
= `[4 xx 22/7 xx (1.75)^2] m^2`
= 38.5 m2
Therefore, the surface area of the sphere having diameter 3.5 m is 38.5 m2.
APPEARS IN
संबंधित प्रश्न
Find the surface area of a sphere of diameter 21 cm.
`["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 hemispherical bowl made of brass has inner diameter 10.5 cm. Find the cost of tin- plating
it on the inside at the rate of Rs. 4 per 100 `cm^2`
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?
The surface area of a sphere is 2464 cm2, find its volume.
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.
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 radius of a sphere whose surface area is 154 cm2.
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 hollow sphere of internal and external diameters 4 cm and 8 cm respectively melted into a cone of base diameter 8 cm, then find the height of the cone.
The total surface area of a hemisphere of radius r 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 sphere is placed inside a right circular cylinder so as to touch the top, base and lateral surface of the cylinder. If the radius of the sphere is r, then the volume of the cylinder is
A cone and a hemisphere have equal bases and equal volumes the ratio of their heights is
Find the surface area and volume of sphere of the following radius. (π = 3.14)
4 cm
Find the radius of a sphere whose surface area is equal to the area of the circle of diameter 2.8 cm
The given figure shows the cross-section of a cone, a cylinder and a hemisphere all with the same diameter 10 cm and the other dimensions are as shown.
Calculate :
- the total surface area.
- the total volume of the solid and
- the density of the material if its total weight is 1.7 kg.
The volume of a sphere is 905 1/7 cm3, find its diameter.
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?
