Question

A hollow iron pipe is 21 cm long and its external diameter is 8 cm. if the thickness of the pipe is 1 cm and iron weighs 8 g/cm3, then the weight of the pipe is?

Answer 1

volume of outer cylinder=2pi r^{2}h
                                       =4224
volume of inner cylinder=2pi r^{2}h
                                      =3234
volume of pipe =4224-3234
                       =990
990*8=7920g/m^{3}