Question

Find the Mass of a cylindrical iron pipe 2.1m long and 12cm in external diameter,if the metal is 1cm thick and of density 7.8g/come(take π to be 22/7)

Answer 1

Find the Mass of a cylindrical iron pipe 2.1m long and 12cm in external diameter ,if the metal is 1cm thick and of density 7.8 g/cm³ (take π to be 22/7).

volume of pipe = external volume - internal volume

                        =(π*R²*L)-(π*r²*L)

                        =(22/7*12²*(2.1*10^-2))-(22/7*(12-1)²*(2.1*10^-2))

                        =9.504-7.986=1.518 cm³ 

mass of pipe=density*volume=7.8*1.518=11.8404 gm.