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