Question

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.​

Answer 1

Answer:

Step-by-step explanation:

Answer 2

$\Large{\textbf{\underline{\underline{According\:to\:the\:Question}}}}$

Given,

Height = 2.8 m

Change in cm³

= 280 cm³.

Diameter

d = 20 cm.

Radius

$\tt{\rightarrow\dfrac{Diameter}{2}}$

$\tt{\rightarrow\dfrac{20}{2}}$

= 10 cm.

$\Large{\boxed{\sf\:{Volume\;of\;Cylinder}}}$

= πr²h

$\tt{\rightarrow\dfrac{22}{7}\times (10)^2 \times 2.8}$

= 88000 cm³.

Also,

Height (h) = 42 cm.

Radius (r) = 10 cm.

$\Large{\boxed{\sf\:{Volume\;of\;Cone}}}$

$\tt{\rightarrow\dfrac{1}{3}\times \pi r^2h}$

$\tt{\rightarrow\dfrac{1}{3}\times\dfrac{}{}\times 10^2 \times 42}$

= 4400 cm³.

$\Large{\boxed{\sf\:{Volume\;of\;Pillar}}}$

= Volume of cylinder + Volume of Cone

= 88000 + 4400

= 92400 cm³

Weight of 1 cm³ of iron

= 7.5 g.

$\Large{\boxed{\sf\:{Weight\;of\;Pillar}}}$

= 7.5 × 92400

= 693000 g

= 693 kg