Question

A steel pipe is 35cm long and it's external diameter is 10 cm . If the thickness of the pipe is 2cm and steel weighs 6 g per cm cube find the weight of the pipe?

Answer 1

D = 10 cm
Radius = 5cm,
R1 = 5cm
R2 = 5-2 = 3cm
$\pi \times h \times (r {1}^{2} - r {2}^{2} ) \\ 22 \times 35 \times (5 {}^{2} - 3 {}^{2} ) \div 7 \\ 110 \times (25 - 9) \\ 110 \times 16 = 1760 \: cm {}^{3}$
$weight \: of \: 1cm {}^{3} pipe \: = \: 6g \\ thus \: weight \:of \: 1760 {cm}^{3} = 1760 \times 6 = 10560g \: = 10.56kg$