Question

a well is 21m. long and its exterior diameter is 7m. if the thickness of the pipe is 1cm. and iron weight is 8gm/cm^3. find weight of pipe .

Answer 1

Answer:

Step-by-step explanation:

Lenght=21m=21*100=2100cm which is height (* means multiplied)

Exterior diameter=8cm

Radius=d/2

=8/2

=4cm

Let us take exteror radius as R

Thickness=1cm

 Interior radius=exterior(outer) radius-thickness

                    =4-1

                  =3cm(let inner radius be r)

volume of pipe (which is hollow)

=π(R square-r square)*height

                                                 

 =22/7(4 square-3 square)*2100

                                                    =22/7(16-9)*2100

                                                     =22/7*7*2100

                                                     =46200cubic cm

weight = 46200*8

           =369600gram

            =369.6kilogram