A hollow iron pipe is 2 m long. Its external diameter is 10 cm and it is 1 cm thick. Calculate the weight of

the pipe if iron weighs 8.2 g/cm3

.

Guest May 19, 2020

#1**+3 **

The volume of the pipe is just the difference in the volumes of two cylinders =

Volume of "outside" cylinder - Volume of "inside" cylinder =

{2m = 200cm)

pi * ( 11/2)^2 * 200 - pi * (10/2)^2 * 200 =

200pi [ 5.5^2 - 5^2 ] =

200pi * 5.25 =

1050 pi cm^3

So....the weight is

1050 pi cm^3 * (8.2)g / cm^3 = [8610 pi] g ≈ 27049 g

CPhill May 19, 2020

#2**0 **

Hey CPhill!

I don't get the part where

pi * ( 11/2)^2 * 200 - pi * (10/2)^2 * 200 =

can u please explain thanks.

Guest May 19, 2020

#4**+2 **

I think that should be 9/2 rather than 11/2

like this:

pi * ( 10/2)^2 * 200 - pi * (9/2)^2 * 200

ElectricPavlov May 19, 2020