Advertisements
Advertisements
प्रश्न
There is a ratio 1: 4 between the surface area of two spheres, find the ratio between their radius.
Advertisements
उत्तर
Let radius of spheres are r1 and r2.
So, surface area of spheres is 4πr12 and 4πr22.
Ratio of surface area = `(4πr_1^2)/(4πr_2^2) = 1/4`
= `(r_1^2)/(r_2^2) = 1/4`
= `((r_1)/(r_2))^2 = 1/4`
= `(r_1)/(r_2) = sqrt(1/4)`
= `(r_1)/(r_2) = 1/2`
Hence, the ratio between their radius = 1: 2.
संबंधित प्रश्न
The volume of a sphere is 38808 cm3; find its diameter and the surface area.
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.
The total surface area of a hemisphere of radius r 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 sphere has the same curved surface area as the curved surface area of a cone of height 36 cm and base radius 15 cm . Find the radius of the sphere .
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 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.
A conical tent is to accommodate 77 persons. Each person must have 16 m3 of air to breathe. Given the radius of the tent as 7 m, find the height of the tent and also its curved surface area.
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 vessel is in he form of an inverted cone. Its height is 11 cm., and the radius of its top which is open is 2.5 cm. It is filled with water up to the rim. When lead shots, each of which is a sphere of radius 0.25 cm., are dropped 2 into the vessel, `2/5`th of the water flows out. Find the number of lead shots dropped into the vessel.
