An iron pillar consists of a cylindrical portion of 2.8 m. height and 20 cm. in diameter and a cone of 42 cm. height surmounting it. Find the weight of the pillar if 1cm3 of iron weighs 7.5 g.
Answers
Answer: 693 kg
Step-by-step explanation:
Let the height of the cylindrical portion be H and height of cone be h.
Radius of base is same for both portion. Let the radius be r
Now Given;
H = 2.8 m = 2.8×100 cm = 280cm
h = 42 cm.
2r = 20 cm
r = 10 cm
Calculate the Volume of Cylindrical Portion:-
V₁ = πr²H
V₁ = 22/7 × 10² × 280
V₁ = 22 × 100 × 40
V₁ = 88,000 cm³
Calculate the volume of Cone:-
V₂ = 1/3 × πr²h
V₂ = 1/3 × 22/7 × 10² × 42
V₂ = 1/3 × 22 × 100 × 6
V₂ = 22 × 100 × 2
V₂ = 44,00 cm³
Total volume of pillar = V₁ + V₂
= 88000 + 4400
= 92400 cm³
Weight of 1 cm³ = 7.5 g
Weight of 92400 cm³ = 7.5×92400
= 693,000 gram.
= 693 kg
