Advertisements
Advertisements
Question
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.
Advertisements
Solution
External radius (R) = 14 cm
Internal radius (r) = `21/2` cm
`2/3pi(R^3 - r^3)`
= `2/3 xx 22/7((14)^3 - (21/2)^3)`
= `44/21(2744 - 1157.625)`
= `44/21 xx 1586.375`
= `3323.83 "cm"^3`
RELATED QUESTIONS
Find the surface area of a sphere of diameter 21 cm.
`["Assume "pi=22/7]`
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.
The diameter of the moon is approximately one-fourth of the diameter of the earth. Find the ratio of their surface area.
Find the surface area of a sphere of diameter 21 cm.
Find the total surface area of a hemisphere and a solid hemisphere each of radius 10 cm.
(Use ЁЭЬЛ = 3.14)
The volume of one sphere is 27 times that of another sphere. Calculate the ratio of their :
- radii,
- surface areas.
Spherical marbles of diameter 1.4 cm are dropped into beaker containing some water and are fully submerged. The diameter of the beaker is 7 cm. Find how many marbles have been dropped in it if the water rises by 5.6 cm.
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.
A cylindrical rod whose height is 8 times of its radius is melted and recast into spherical balls of same radius. The number of balls will be
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.
