inner Suit
A cylindrical iron pillar of diameter 14 dm and height 14 dm is surmounted by a cone
9 dm high. Find the weight of the iron pillar, if 1 cubic dm of won weigh 9.6
Answers
Given,
An iron pillar consists of a cylindrical portion and a cone mounted on it.
The height of the cylindrical portion of the pillar, H=2.8 m=280 cm
The height of the conical portion of the pillar, h=42 cm
The diameter of the cylindrical portion of the pillar = diameter of the circular base of cone =D=20 cm
The radius of the circular base of cylinder/ cone r=
2
D
=10 cm
Now,
Volume of the pillar, (V)= Volume of the cylindrical portion of pillar + volume of the conical portion of the pillar.
→V=πr
2
H+
3
1
πr
2
h
→V=(
7
22
×10
2
×280+
3
1
×
7
22
×10
2
×42) cm
3
→V=(22×100×40+22×100×2) cm
3
→V=(88000+4400) cm
3
→V=92400 cm
3
Hence, volume of iron pillar is 92400 cm
3
Given,
Weight of 1 cm
3
iron =7.5 gm.
Hence, weight of 92400 cm
3
iron =7.5×92400 gm.
=693000 gm.
=693 Kg. ∵1Kg=1000 gm.
Hence, the weight of iron piller is 693 Kg.
