Question

A yellow cylindrical pipe is made of iron. Its external and internal radii are 8 cm and 7 cm respectively and it is 35 cm long .If 1 $c{m}^3$ iron weight 8 g then the weight of the pipe is

• A. 13.25 kg
• B. 13.2 kg
• C. 13.26 kg
• D. 13.21 kg

Answer 1

The correct option is B 13.2 kg

Volume of material = $\pi (R^2-r^2)h$
= $\frac{22}{7}(8+7)(8-7)\times 35c{m}^3=1650c{m}^3$
Weight = 1650 x 8 gm = 13200 gms = 13.2 kg