Question

An iron pipe is 21 cm long and its external diameter is 8cm. If its thickness is 1cm and the iron weighs 8gm/cm^3, find the weight of the pipe

Answer 1

Answer:

Step-by-step explanation:

the pipe is a cyclindrical object

external radius = 8cm

internal radius = 8-1 = 7cm

volume of the thickness = external cyclinder volume - internal cyclinder volum

                                       = πr²h) external - πr²h)internal

height = 21 cm

                                   = π8²×21 - π7²×21

                                   = 21π (64-49)

                                    = 21π×15 = 21×22×15/7 = 3×22×15 = 990cm³

 iron weighs = 8gm/cm³

990×8 = 7920 gram = 7.92 kg                              

Answer 2

Heyaa!

Your answer is in the above attachment.

hope it helps