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 8 g mass. (Use π = 3.14)

(a) 982.62 kg 

(b) 892.26 kg 

(c) 829.26 kg 

(d) 928.62 kg

Answer 1

Answer: (b) = 892.26 kg

Mass of pole = Volume of pole × 8g. 

Volume of pole = Vol. of base cylinder + Vol. of top cylinder 

= π × (12)² × 220 +π × (8)² × 60

Taking π =3.14

= 3.14 × 144 × 220 + 3.14 × 64 × 60

= 99475.2 + 12057.6 cm³

= 111532.8 cm³

∴  Mass of pole = 111532.8 × 8  

= 892262.4 g

= 892.2624 kg

= 892.26 kg