There is a solid iron - pillar in front of Anil's house , the lower part of which is of type of right circular cylinder and the upper part is of type of a right circular cone . The radii of their diameter of bases is 20 cm . If the height of the cylindricalpart be 2.8 metres and that of the conical part be 42 cm and if the weight of 1 cc iron be 7.5 gm , then what will be the weight of the pilar ?

Explanation

The diameter of the buses = 20 cm
` :.` The radii of the bases = ` 20/2 ` cm = 10 cm
The height of the cylindrical part = 2.8 metres = 280 cm
` :.` the volume of this part ` = 22/7 xx (10)^(2) xx 280 " cc"`
` = 22/7 xx 100 xx 280 " cc"`
88000 cc
again , the height of the conical part = 42 cm
` :.` the volume of the conical part ` 1/3 xx 22/7 xx (10)^(2) xx 42 " cc"`
` = 1/3 xx 22/7 x 100 x 42 "cc"`
` = 1/3 xx 22/7 xx 100 xx 42 "cc"`
So , the total volume of the pillar = `(88000 + 4400)` cc
` :. ` the weight of the total pillar ` = (7.5 xx 92400) `gm
= 693000 gm
= 693 kg
Hence the required weight = 693 kg