Question

A solid iron pole consists of a cylinder of height 220 cm and base diameter 24 cm, which is surmounted by another cylinder of height 60 cm and radius 8 cm. (Find the mass of the pole, given that 1 cm³ of iron has approximately 8g mass. (Use π = 3.14).

Answer 1

Height of solid iron pole, h = 220 cm. 

Base diameter of pole, d = 24 cm. 

∴ Radius, r = 12 cm. 

Height of cylinder, h = 60 cm. 

Radius of cylinder, r= 8 cm. 

Mass of the pole = ? 

Volume of 1st Cylinder, V = πr²h 

= π × (12)² × 220 

Volume of 2nd cylinder, V = πr²h 

= 77 × (8)² × 60 

∴ Total Volume = π × (12)² × 220 + π × (8)² × 60 

= {144 × 220 + 64 × 60}π 

= 35520π 

= 111532.8 cm³ . 

Mass of iron about 1 ccm is 8 gm. 

∴ Mass of iron 111532.8 ……. ?? 

\(= \frac{111532.8\times 8}{1000}kg\)

= 111.5328 × 8 kg. 

= 892.26 kg.