Question

An iron pillar has some part in the form of a right circular cylinder and remaining in the form of a right circular cone. The radius of the base of each of cone and cylinder is 8 cm. The cylinderical part is 240 cm high and the conical part in 36 cm high. Find the weight of the pillar if one cu. cm of iron weighs 7.8 grams.​

Answer 1

Answer:

pillar has some part in the form of a right circular cylinder and remaining in the form of a right circular cone. The radius of the base of each of cone and cylinder is 8 cm. The cylinderical part is 240 cm high and the conical part in 36 cm high. Find the weight of the pillar if one cu. cm of iron weighs 7.8 grams.

Answer 2

${\sf{\purple{\underline{\overline{Given:-}}}}}$

Radius = 8 cm

Height of cylinder = 240 cm

the conical part in 36 cm high.

${\sf{\pink{\underline{\overline{To \: find:-}}}}}$

Weight of the pillar if one cu. cm of iron weighs 7.8 grams.

${\sf{\purple{\underline{\overline{Solution :-}}}}}$

$\sf \fbox \red {We know that}$

Volume of cylinder = πr²h

Volume of cone = ⅓πr²h

Now,

Volume of cylinder = 3.14 × 8 × 8 × 240

=> 48320.4 cm^3

Now,

⅓ × 3.14 × 8 × 8 × 36

1 × 3.14 × 8 × 8 × 12

3.14 × 64 ×12

2411.52 cm^3

Now,

Weight of pillar = Volume of cylinder + volume of cone

W = 48320.4 + 2411.52

W = 50730

Now,

1kg = 1000gm

7.8/1000 × 50730

0.0078 × 50730

395.4 kg

Weight of pillar is 395 kg.

${\sf{\purple{\underline{\overline{❀Tʜᴀɴᴋs!!}}}}}$