Advertisements
Advertisements
Question
The dome of a building is in the form of a hemisphere. Its radius is 63 dm. Find the cost of painting it at the rate of Rs. 2 per sq. m.
Advertisements
Solution
Dome Radius − 63 dm − 6.3m
Inner S.A of dome = `2πr^2 − 2 × 22/7 × (6.3)^2 − 249.48 m^2`
Now, the cost of `1m^2` = Rs. 2.
∴ Cost of `249.48m^2` − Rs [2 × 249.48]
= Rs. 498.96.
RELATED QUESTIONS
A model of a ship is made to a scale 1: 300
1) The length of the model of the ship is 2 m. Calculate the lengths of the ship.
2) The area of the deck ship is 180,000 m2. Calculate the area of the deck of the model.
3) The volume of the model in 6.5 m3. Calculate the volume of the ship.
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.
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:
- the radius of the sphere.
- the number of cones recast. (Take π = `22/7`)
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 radius 14 cm.
Find the surface area of a sphere of diameter 14 cm.
The surface area of a sphere is 5544 `cm^2`, find its diameter.
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`
A cylinder of same height and radius is placed on the top of a hemisphere. Find the curved
surface area of the shape if the length of the shape be 7 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.
The diameter of a sphere is 6 cm. It is melted and drawn into a wire of diameter 0.2 cm. Find the length of the wire.
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 largest sphere is cut off from a cube of side 6 cm. The volume of the sphere will be
If a sphere is inscribed in a cube, then the ratio of the volume of the sphere to the volume of the cube 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
Find the surface area and volume of sphere of the following radius. (π = 3.14 )
9 cm
Find the surface area and volume of sphere of the following radius. (π = 3.14 )
3.5 cm
If the surface area of a sphere is 2826 cm2 then find its volume. ( π= 3.14)
Find the radius of a sphere whose surface area is equal to the area of the circle of diameter 2.8 cm
Find the radius of the sphere whose surface area is equal to its volume .
The internal and external diameters of a hollow hemi-spherical vessel are 21 cm and 28 cm respectively. Find volume of material of the vessel.
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.
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 hemispherical balloon increases from 6 cm to 12 cm as air is being pumped into it. The ratios of the surface areas of the balloon in the two cases is ______.
